Abstract:
A system comprising structures connected to the rider of human-powered vehicles improves the force a rider may apply to the vehicle. The elements are primarily connected to the lower body and legs of the rider, with attachment to the rider&#39;s shoes, whereby a two-dimensional four-bar linkage is formed. Use of the system may permit a rider to go faster or farther with less effort. An optional novel shoe may be used with or without the other elements of the system.

Description:
BACKGROUND 
     Bicycles are a popular and efficient form of transportation, with a long history of invention and improvement. Many communities are developing an ever-growing matrix of bike paths, encouraging people to ride a bike to work as a way to both improve health and lower greenhouse gas generation. As bike riding has become more popular, so too has physical training and conditioning to improve one&#39;s bike riding performance. There are many products now available to measure a rider&#39;s performance, intended to provide motivation to perform better and/or improve conditioning, which may lead to better performance. There are many bike riding accessories and improvements in equipment to provide somewhat better performance. In some cases such equipment may not be permitted during competition but are used by riders to improve their performance when not using the equipment. Such equipment may be of interest to those that do not compete simply to improve their experience, perhaps enabling them to ride farther or faster than they otherwise may be able to do. 
     SUMMARY 
     A system for improving a person&#39;s pedaling efficiency is disclosed herein. The system couples rotation of a person&#39;s foot connected with a pedal on a human-powered vehicle with rotation of a corresponding thigh. When torque is applied by the foot with a plantar flexion, the system transfers the torque to a corresponding thigh. This results in hip extension, thereby adding force to assist in pushing the pedal downward. The system is a passive mechanical linkage, with all power provided by the legs of the rider. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate exemplary aspects of the invention, and, together with the general description given above and the detailed description given below, serve to explain features of the invention. 
         FIG. 1  is a perspective view of the system components. 
         FIG. 2  is a perspective view of the system as worn by a person. 
         FIG. 3  is a side view of the system on a person&#39;s leg with the hip flexed, knee bent, and foot parallel to the thigh. 
         FIG. 4  is a side view of the system on a person&#39;s leg with the hip, knee, and toes extended. 
         FIG. 5  is a side view of the system on a person&#39;s leg when in a standing position. 
         FIG. 6  relates geometric relationships between the various structural members of the disclosed system. 
         FIG. 7  is a view of the system as worn by a person riding a bicycle. 
         FIG. 8  is a detailed view of an optional shoe, adapted to cooperate with the system. 
     
    
    
     DETAILED DESCRIPTION 
     The various embodiments will be described in detail with reference to the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. References made to particular examples and implementations are for illustrative purposes, and are not intended to limit the scope of the invention or the claims. 
     To make the disclosure more clear, references relative to “left” or “right” are interchangeable. Also, elements that are referenced on one side of the system will carry the same reference number as the same element on the other side of the system. The plural may apply to the singular, and the singular may apply to the plural in all references and in the description. 
     The instant invention may be beneficial when used while operating any pedal-powered apparatus. Examples include rickshaws, basic electricity generators, pumps (such as emergency pumps), and of course bicycles providing for any number of riders. 
       FIG. 1  is a perspective drawing of the components comprising a system  100 . The system  100  comprises outer thigh linkages  102 , connected to a body harness  104  by hinged connectors  105 . The connectors  105  may allow rotation of the outer thigh linkages  102  relative to the body harness  104 . Cables  115 ,  116 , sometimes collectively denominated as a “coupler”, connect outer thigh linkages  102  to shoes  112 . The coupler comprises one or two wires  115 ,  116 . 
     An upper thigh brace  120  and a lower thigh brace  125  are connected to the outer thigh linkages  102  on the braces&#39;  120 ,  125  outside ends and inner thigh linkages  130  at the braces&#39;  120 ,  125  inner edges. Optionally, the thigh braces  120 ,  125  may also be connected with each other by top connectors  135 . Straps  108  connecting the outer thigh linkages  102  to the inner thigh linkages  130  complete an encircling attachment, thereby capturing a rider&#39;s thigh  107  ( FIG. 2 ). A strap  140 , connected to the hinges  105 , may go under a rider&#39;s buttocks to secure the body harness  104 . In some embodiments only a single coupler ( 115  or  116 ) is provided, though providing both may provide better stability to the rider&#39;s foot and prevent rotation of the linkages  102 ,  130  and thigh braces  120 ,  125  about the longitudinal axis of the thigh  107 . 
     Looking to  FIG. 2 , we see a perspective drawing of the system  100  as worn by a person  101 . In some embodiments the outer thigh linkages  102  extend past the wearer&#39;s knees, thereby providing clearance for the couplers  115 ,  116 . In some embodiments pads  127  may be placed underneath the uppermost thigh braces  120  for comfort. 
       FIG. 2  further illustrates couplers  115 ,  116  connecting the outer thigh linkages  102  and  130  to shoes  112  worn by a rider. A plate  122  under the rider&#39;s shoe  112  connects to the coupler  115 ,  116  and thereby to the outer thigh linkages  102 . The plate  122  may be rigid, for example comprised of metal, or flexible. 
       FIG. 3  and  FIG. 4  show an example of operation of the system.  FIG. 3  is a side view of the system  100  attached to a rider&#39;s leg  107  while the hip is flexed. As viewed from the side, the system approximates a two-dimensional four-bar linkage or pantograph. The shoe  112  and outer thigh linkage  102  provide the rotating cranks. The shin  119  and coupler  115 ,  116  provide the couplings, whereby movement of the shoe  112  causes rotation of the outer thigh linkage  102 . 
       FIG. 4  is a side view of the system  100  with the wearer&#39;s leg extended and the shoe  112  rotated with the toe downward, as may occur while pedaling a bicycle. Note that the shoe  112  and outer thigh linkage  102  may be rotated together in the plane of motion. The outer thigh linkage  102  is connected to the body harness  104  at the hip, such that the thigh  107  and outer thigh linkage  102  have a common axis of rotation. 
       FIG. 5  is a side view of the system  100  attached to a wearer&#39;s leg wherein the wearer is in a standing position. The coupler  115 ,  116  is slack, thereby permitting a comfortable standing position. The standing position might be difficult if the coupler  115 ,  116  were instead rigid. 
       FIG. 5  also illustrates the coupler  115 ,  116  flexing to allow plantar extension (the shoe  112  approximately orthogonal to the longitudinal axis of the leg) while the hip is extended (the outer thigh linkage  102  nearly vertical). The flexible coupler  115 ,  116  allows a bicycle rider to raise his toes to avoid small obstacles on the ground. This feature may be useful when the bicycle is leaning to one side for turning, since one pedal would be closer to the ground than the other. 
       FIG. 6  is a side view of the system  100  attached to one leg, illustrating lengths and adjustments of the various elements. Length  124  is the distance between the knee and coupler  115 ,  116 . Length  125  is the distance between the ankle and coupler  115 ,  116 . The relative rotation of the shoe  112  and the outer thigh linkage  102  depends on the ratio of length  124  to length  125 . Length  124  may be adjusted by attaching the coupler  115 ,  116  to different points on the outer thigh linkage  102 . Length  125  may be adjusted by attaching the coupler  115 ,  116  to different points on the shoe  112 . 
     Length  126  is the distance between a wearer&#39;s knee and ankle. Length  127  is the length of the coupler  115 ,  116 . Length  126  and length  127  may be approximately equal, such that the ankle is extended when the hip is flexed. The length of the coupler  115 ,  116  may be adjusted to provide an offset between ankle rotation and hip rotation. 
     Length  128  is the distance between the person&#39;s waist and the thigh linkage connector  105 . Length  128  aligns the outer thigh linkage  102  with the thigh, such that the thigh linkage and thigh are aligned, and move together comfortably. Length  128  may be adjusted to match the size and shape of the wearer. 
       FIG. 7  shows the system  100  on a bicyclist with a shoe  112  on a pedal  123 . The pedal  123  is approximately below the ankle. The coupler  115 ,  116  connects to the shoe  112  near the ball of the foot, forward of the pedal  123 . Standard bicycle shoes typically place a pedal cleat under the ball of the foot. System performance is enhanced with the shoe  112  positioned relative to the pedal  123  as shown in  FIG. 7 . 
     Bicycle riders may need to become accustomed to the new shoe position shown in  FIG. 7 . For training purposes, a shoe could allow a range of pedal placement. Beginners could start with a standard pedal placement, and gradually adjust to the pedal position shown in  FIG. 7 . 
     Looking now to  FIG. 8 , a novel shoe  112  is shown in greater detail. In some embodiments a rider wears regular riding shoes with the plate  122  positioned under the ball of the foot. The coupler  115 ,  116  may connect to the plate  122  directly or through hinges  121 . In some embodiments a novel shoe is worn, wherein the sole of the novel shoe includes a clipless connector  124  approximating the position of the ball of the foot with channels running front to back, and the plate  122  has fasteners  123  connected with the clipless connector  124  to rigidly connect the plate  122  to the connector  124 , and thereby to the shoe  112 . The connector  124  channel may be extended in the longitudinal direction of the foot, thereby providing the wearer the ability to increase of decrease the length of the moment arm between the plate  122  and a rider&#39;s ankle. The rigid plate  122  reinforces the shoe  112  to prevent bending under load. The shoe  112  may also include a cleat  126  for rigid attachment to a pedal  123  ( FIG. 7 ) on the bike. In some embodiments the cleat  126  is adjustable, to allow positioning to accommodate different pedaling styles and foot positions. 
     The connector  124  allows positioning of the plate  122  to accommodate different pedaling styles and foot positions. The connector  124  allows the plate  122  to be replaced with a standard clipless pedal cleat, giving the user the option of riding with the rigid plate  122  and the system  100 , or a clipless pedal cleat without the system  100 . That is, the shoe  112  is useful both with and without the other elements of system  100 . 
     The preceding description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the following claims and the principles and novel features disclosed herein.