Linkage energy return shoe

Abstract

The key feature of the “linkage energy return shoe” is a compressible sole comprising a sole linkage which constrains the upper shoe plate to not tilt, in one embodiment, and to follow a controlled compression path, in general. A consequence of the anti-tilt feature inherent in the sole linkage is that a spring located anywhere in the sole resists sole compression at both the toe section and the heel section. Thus, one or two springs or stops suffice, and the modular design makes it a simple matter to change springs to tune the bow shoe to an individual's weight and gait and to change shoe and ground plates for different size feet. The spring system can easily give a constant force curve, a linear force curve, or any force curve in between—thereby permitting faster running for a given maximum force and thereby reducing impact injuries.

1 . In a shoe a linkage energy return shoe sole for walking, running, and jumping by a wearer comprising 
 an upper sole plate,    a lower sole plate,    a combined energy return linkage comprising one or more energy return linkages, wherein each said energy return linkage comprises at least one 4-bar linkage comprising four links hingeably interconnected at link hinges, wherein each link rotates in the longitudinal front-to-back plane formed by a vertical line and by a line extending from the front to back of said linkage energy return shoe sole,    a spring system to store and return energy of compression of said linkage energy return shoe sole, wherein said spring system comprises at least one spring, wherein each one spring may act between any two locations on said combined energy return linkage, wherein the range action of each one spring may be restricted by various types of stops, and    a foot attachment means to attach said linkage energy return shoe sole to the foot of said wearer, wherein said foot may be that of a person, a foot prosthesis, or a robot.    
   
   
       2 . The linkage energy return shoe sole of  claim 1  wherein said combined energy return linkage comprises links of various lengths, wherein opposing said links may or may not be parallel, wherein said upper sole plate may or may not be parallel to said lower plate, wherein the thickness of the front of said linkage energy return shoe sole may less or more than the thickness of the back of said linkage energy return shoe sole.  
   
   
       3 . The linkage energy return shoe sole of  claim 1  wherein said upper sole plate comprises a push-off means which allows said wearer to flex his metatarsal joint and push off his toe during toe-off.  
   
   
       4 . The linkage energy return shoe sole of  claim 1  wherein said bottom sole plate comprises a curved bottom wherein said curved bottom which comprises a curled toe, wherein said bottom sole plate is rigid.  
   
   
       5 . The linkage energy return shoe sole of  claim 3  wherein said push-off means comprises a push-off frame hingeably connected to said upper sole plate by a toe hinge and extending rearward, and fixedly attached to the rear foot of said wearer, wherein both the heel of said wearer and said push-off frame are free to rotate about said toe hinge and away from the rear section of said upper sole plate.  
   
   
       6 . The linkage energy return shoe sole of  claim 3  wherein said push-off means comprises a particular location and shape of said curled toe, wherein said linkage energy return shoe sole rocks forward throughout toe-off about the rolling bearing formed by said curled toe.  
   
   
       7 . The linkage energy return shoe sole of  claim 1  wherein said combination linkage comprises one or more guided p-diamond linkages each of which comprises nine links further comprising 
 four diamond links,    two end links,    a top length link,    a center length link,    a bottom length link, wherein said nine links are hingeably connected by link hinges, wherein said top length link is rigidly attached to said upper sole plate, and said bottom length link is rigidly attached to said lower sole plate, wherein the four said diamond links are hingeably interconnected by said link hinges to form a diamond shape, with two top links and two bottom links, wherein two interconnecting diamond links, one of which is a bottom link, are called outside diamond links because they face away from the center of said p-diamond and the other two diamond links are called inside diamond links, wherein a top link hinge connecting the top two said diamond links is hingeably connected to said top length link, wherein a bottom link hinge connecting the bottom two diamond links is hingeably connected to said bottom length link, wherein the two said outside diamond links are hingeably connected by a link hinge called the outside link hinge, and the two inside diamond links are hingeably connected by a said link hinge called the inside link hinge, wherein said top length link is also hingeably connected to one of said end links, and said bottom length is also hingeably connected to the other one of said end links, wherein said end links are hingeably interconnected by a link hinge called the end center link hinge, wherein said center length link is connected to said inside link hinge and said end center link hinge, wherein the overall configuration of said nine links of said p-diamond linkage (for the particular but not the required case when all diamond links and end links are the same length) is two parallelograms and a diamond which overlap one another and that is why the invention is referred to as a p-diamond, wherein the two said outside diamond links constrain said p-diamond to compress in such a manner that said top length link remains parallel to said bottom length link which means said p-diamond compresses without tilting, and    a mid-link front vertex guide rigidly extending along and from said center length link to make a key constraint on said outside link hinge to move within and along said mid-link front vertex guide, along the continuation line extending along the length of said mid length link, wherein said upper sole plate is constrained to move exactly vertically (with no tilting) with respect to said lower sole plate for the case when all of said diamond links and said end link have the same lengths, wherein said upper sole plate is constrained to move in a prescribed trajectory with the designed vertical travel with controlled tilting with respect to said lower sole plate for the case when all of said diamond links and said end links do not have the same lengths which is the case when the thickness of the front of said linkage energy return shoe sole is less than the thickness of back of said linkage energy return shoe sole.    
   
   
       8 . The linkage energy return shoe sole of  claim 7  wherein said spring system comprises one or more horizontal springs acting said inside link and said center length link, wherein said one or more horizontal springs may be attached at any location along the length of said center length link, wherein said one or more horizontal springs may be one of many types such as helical springs, leaf springs, or curved bow springs.  
   
   
       9 . The linkage energy return shoe sole of  claim 8  wherein said horizontal spring has a force curve which allows the vertical force curve of said spring system to be approximately constant over the compression of said p-diamond.  
   
   
       10 . The linkage energy return shoe sole of  claim 7  wherein said upper sole plate comprises a half-height sole comprising half-height hangars which extend downward from the level of the top of said top links and the level of the top of the top one of said end links to a level of approximately one-half that height—to fixedly attach to a half-height foot plate, thereby reducing the effective height of said linkage energy return shoe sole by a half and improving lateral sole stability.  
   
   
       11 . The linkage energy return shoe sole of  claim 1  wherein said combination linkage is a p-linkage comprising four p-links which hingeably interconnect via said link hinges to form a parallelogram.  
   
   
       12 . The linkage energy return shoe sole of  claim 1  wherein said combination linkage is a 2p-linkage comprising seven 2p-links which form two parallelograms with a shared link.  
   
   
       13 . The linkage energy return shoe sole of  claim 11  wherein said a p-linkage comprises a stretched-p linkage comprising one or pairs of stretched links hingeably interconnected at a stretched link hinge and hingeably connected to a top and a bottom left-most of said link hinges on the front side or on the back side, or on both front and back sides, wherein a stretched spring between one of stretched hinge and another stretched hinge resists compression of said p-linkage, wherein a stretched spring acts between said stretched hinge and an opposing one of said link hinges for the case when only one said pair of stretched links is used.  
   
   
       14 . The linkage energy return shoe sole of  claim 11  wherein said p-linkage comprises a hanging-p linkage comprising one or more p-extension hinges on the ends of p-link extensions which rigidly extend from front and back said p-links outward and toward the height center (diagonally downward for an upper said p-link and diagonally upward for a lower said p-link), wherein a lengthwise said spring is hingeably connected between the front and back said p-extension hinges, wherein interference of lengthwise said spring with other elements of said hanging-p linkage is reduced during compression of said hanging-p linkage.  
   
   
       15 . The linkage energy return shoe sole of  claim 1  which further comprises a bow shoe for use by a wearer, wherein said spring system comprises 
 a bow spring located above said upper sole plate and hingeably connected to said upper sole plate,    a leg attachment means for attaching said bow spring to the leg of said wearer,    a suspension system connecting the top of said bow spring to said lower sole plate, wherein the force of both the wearer's toe and heel cause said bow spring to be loaded throughout foot-strike, wherein heel impact energy is not returned prematurely at the beginning of to push-off, but rather is returned optimally during toe-off during the latter part of push-off.    
   
   
       16 . The linkage energy return shoe sole of  claim 12  wherein said suspension system comprises 
 one or more ankle-pivot supports rigidly attached to said lower sole plate and extending around and above the level of the foot of said wearer,    one or more ankle-pivot housings rigidly attached to said ankle-pivot support and housing an ankle pivot,    one or more cords attached to said upper sole plate and passing around the foot of said wearer and through said ankle-pivot housings, and    a cord guide to constrain said cords to the location of said ankle-pivot.    
   
   
       17 . The linkage energy return shoe sole of  claim 12  wherein said suspension system further comprises a shin-level bow spring assembly comprising 
 a bow spring pivotly attached to said ankle-pivot housing,    a bow guide pivotly attached to said ankle-pivot housing and to the top of said bow spring, wherein said bow guide changes length telescopically,    a shin slider slidingly attached to the top of said bow guide, and    a shin strap for attaching said shin slider to the shin of said wearer, wherein said cords extend to connect to the top of said bow spring, wherein the impact force of said wearer's foot on said shoe plate loads said bow spring via said cords.    
   
   
       18 . A guided p-diamond shoe sole for walking, running, and jumping by a wearer comprising a guided p-diamond sole comprising 
 an upper sole plate,    a lower sole plate,    one or more guided p-diamond linkages each of which comprises nine links further comprising    four diamond links,    two end links,    a top length link,    a center length link,    a bottom length link, wherein said nine links are hingeably connected by link hinges, wherein said top length link is rigidly attached to said upper sole plate, and said bottom length link is rigidly attached to said lower sole plate, wherein the four said diamond links are hingeably interconnected by said link hinges to form a diamond shape, with two top links and two bottom links, wherein two interconnecting diamond links, one of which is a bottom link, are called outside diamond links because they face away from the center of said p-diamond and the other two diamond links are called inside diamond links, wherein a top link hinge connecting the top two said diamond links is hingeably connected to said top length link, wherein a bottom link hinge connecting the bottom two diamond links is hingeably connected to said bottom length link, wherein the two said outside diamond links are hingeably connected by a link hinge called the outside link hinge, and the two inside diamond links are hingeably connected by a said link hinge called the inside link hinge, wherein said top length link is also hingeably connected to one of said end links, and said bottom length is also hingeably connected to the other one of said end links, wherein said end links are hingeably interconnected by a link hinge called the end center link hinge, wherein said center length link is connected to said inside link hinge and said end center link hinge, wherein the overall configuration of said nine links of said p-diamond linkage (for the particular but not the required case when all diamond links and end links are the same length) is two parallelograms and a diamond which overlap one another and which is why the invention is referred to as a p-diamond, wherein the two said outside diamond links constrain said p-diamond to compress in such a manner that said top length link remains parallel to said bottom length link which means said p-diamond compresses without tilting, and    a mid-link front vertex guide rigidly extending along and from said center length link to make a key constraint on said outside link hinge to move within and along said mid-link front vertex guide, along the continuation line extending along the length of and from said center length link, wherein said upper sole plate is constrained to move exactly vertically (with no tilting) with respect to said lower sole plate for the case when all of said diamond links and said end link have the same lengths, wherein said upper sole plate is constrained to move in a prescribed trajectory with the designed vertical travel with controlled tilting with respect to said lower sole plate for the case when all of said diamond links and said end links do not have the same lengths which is the case when the thickness of the front of said linkage energy return shoe sole is less than the thickness of back of said linkage energy return shoe sole,    a spring system to store and return energy of compression of said guided p-diamond sole, wherein said spring system comprises at least one spring and wherein each one spring may act between any two locations on said guided p-diamond linkage and wherein the range action of each one spring may be restricted by various types of stops, and    a foot attachment means to attach shoe sole to the foot of said wearer, wherein said foot may be that of a person, a foot prosthesis, or a robot.