This invention particularly relates to an asymmetrical bicycle pedal which can replace the conventional pedals that are used for transmitting the force applied by the human foot, to the drive train in any human foot powered vehicles that is driven by rotary pedaling. This asymmetrical pedal indirectly enhances the length of the crank arm of those vehicles. When a conventional pedal and this asymmetrical pedal are fitted on similar vehicles and an equal force is applied by the foot on the conventional pedal and on this asymmetrical pedal, the vehicle fitted with this asymmetrical pedal generates greater torque than the vehicle fitted with the conventional pedal. This enhanced torque will help a rider to ride by applying less force or to ride faster by applying the same force with the help of a higher gear ratio of the crank and free wheel.

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The predominant uses of pedals are in human foot powered vehicles. The pedals transmit the force applied on it by a rider, on to a crank arm. The crank arm in turn transmits that power through a drive train, on to the wheels of the vehicle and moves the vehicle forward.There are various types of pedals in use. The basic design of all the pedals remains unchanged and it does not enhance the performance of the vehicles significantly. One such pedal with clips, in combination with shoes which accommodate those clips, aids the rider to apply force almost throughout the rotary pedaling. But the rider has to apply force to lift the pedal through the rear half of the rotary motion of the crank arm and to do so, the weakest muscles in the legs are used. So the enhancement in performance is achieved by using more effort throughout the rotary motion of the pedal. The usefulness of this system except for the purpose of bicycle racing is questionable. The options available to a designer to reduce the effort of a rider by enhancing the torque produced by a given force, is to enhance the length of the crank arm or to use multiple gears as in the case of multi gear bicycles. The length of the crank arm of those vehicles is limited by various factors like ground clearance, ease of operation, etc. Normally, maximum torque develops while the crank arm is in the horizontal position, in the front semicircle of its rotary motion. This asymmetrical pedal as proposed here, indirectly enhances the length of the crank arm in its maximum advantage position while it is in the front half of its rotary motion and produce greater torque. This enhancement is achieved within all the limitations of the length of the crank arm. By using multiple gears on the front crank and on the rear axle of a bicycle, as being done now in the case of multi gear bicycles, this torque can be further increased.

It has already been proposed that the object of this invention is to enhance the torque of any human foot powered vehicles. The principal object of this invention is to enhance the torque of all human foot powered mechanisms that is driven by rotary pedaling as in the case of bicycles, tricycles, quadracycles etc. by indirectly enhancing the length of the crank arm of all such conventional vehicles. The limiting factors that prevent the enhancement of crank arm length of all those vehicles beyond its present lengths are, ground clearance and ease of operation. The proposed asymmetrical pedal can indirectly enhance the crank arm length of those vehicles,with in all those limitations. The proposed asymmetrical pedal can be mounted on the crank arms of all the conventional human foot powered vehicles that is driven by rotary pedaling. This asymmetrical pedal indirectly enhance the crank arm length of all those vehicles through an arc within which the crank arm moves, and this enhancement happens above and below the horizontal position of the crank arm in the front semicircle of its rotary motion. In all other positions of the crank arm during rotary pedaling, this asymmetrical pedal functions just like a conventional pedal. This asymmetrical pedal will be in horizontal alignment at the bottom position of rotary pedaling. So the ground clearance will be the same as in the case of the conventional pedal, which this pedal is proposed to replace.The leg and foot movement of the rider will also be just the same as in the case of a conventional pedal. So this pedal can be used as comfortably as a conventional pedal.

The conventional pedals of all human foot powered vehicles that are driven by roiary pedaling are free to rotate about the axis of its spindle in the forward and reverse directions. The only function of those pedals is to transmit the force applied on it by human foot, to the crank arm upon which it is mounted. This proposed asymmetrical pedal also transmits, the force applied on it by human foot, to the crank arm upon which it is mounted. But the rotation of this pedal about the axis of its spindle, in the forward direction is restricted by a protruding rod and at the same time this pedal is free to rotate in the reverse direction about its spindle. As a result of this restriction of rotation in the forward direction, the effective length of the crank arm upon which this asymmetrical pedal is mounted gets indirectly enhanced by the distance from the axis of the spindle of this asymmetrical pedal to the front foot rest at its front end.This indirect enhancement of the length of crank arm results in the enhancement of the

torque of the mechanism. This enhancement happens from somewhere in the upper half of the front semicircle to somewhere in the lower half of the front semicircle, of the rotary motion of the crank arm. This arc through which the enhancement occurs can be moved to a desired position by adjusting the relative position of the protruding rod to the spindle of this pedal. This proposed asymmetrical pedal comprises of a frame, formed by two separate inverted V shaped parts which are rigidly held together by all the other parts of this pedal. The other parts of this pedal are a front footrest, a rear footrest, a spindle and a spring loaded rod placed inside a tube. All these parts are mounted on the frame of this pedal. The spindle is the same spindle used in conventional pedals to mount the pedal on a crank arm. The front foot rest is a small upward projection forming a bridge connecting the two inverted 'L' shaped parts of the frame, at the front end of the frame. The rear foot rest is a much higher upward projection forming a bridge connecting the two inverted 'L' shaped parts of the frame at the back end of the frame. The spring loaded rod and tube consists of a tube within which a rod and a helical spring are placed with arrangements to restrict the movements of the rod within desired limits. The rod protrudes from the outer face of the pedal frame near the crank arm. The maximum protrusion of the rod is the length required to reach under the crank arm and prevent the forward rotation of the pedal about the axis of its spindle. The surface of the rod coming in contact with the crank arm while the rod is beneath the crank arm is straight and all the other sides of the protrusion are formed in a slanting shape. During rotary pedaling, while the pedal and crank arm are in the top half of the forward semicircle of the crank arm's rotary motion, at a certain position, the protruding rod will get pressed against the crank arm on the top side of the crank arm and as the rotation continues, the crank arm with the help of the slanting shape of the protruding rod, will push the protrudin rod into the tube and disengage it from the crank arm. As the rotation of the crank arm continues farther, the tip of the protruding rod will get pressed against the vertical face of the crank arm near the pedal and as the tip of the protruding rod pass the bottom of the vertical face of the crank arm, the spring inside the tube will push the rod out and the straight portion of the rod will come in contact with the crank arm at the bottom side of the crank arm. This will arrest the forward rotation of the pedal about the axis of its spindle. In this condition the length of the crank arm will get indirectly extended by the distance from the axis of the spindle of the pedal to the front foot rest of the pedal.

This invention is illustrated in the accompanying drawings, throughout which, like reference numerals indicate corresponding parts in the various figures.

Figure 1 shows a plan view of the asymmetrical pedal and Figure 2 shows the front elevation of the asymmetrical pedal and Figure 3 shows a cross section of the asymmetrical pedal along the line marked AA in Figure.1

Referring to the drawings, two inverted ' shaped parts marked 1 are held together rigidly, by all the other parts of this asymmetrical pedal. All the other parts of this asymmetrical pedal are mounted on these two parts marked 1. For the convenience of explaining, these two parts marked 1 will be jointly referred to as, the frame of this pedal. This frame is formed by two separate parts so that the gap between those parts will reduce the weight of the frame. This frame can be made as a single part also by partially or completely filling the gap between those two parts. A front foot rest marked 2 is mounted on the top side of the front end of the frame of this pedal. A rear foot rest, much higher than the front foot rest is marked 3 and is mounted on the topside of the back end of the frame of this pedal. A spindle used in this asymmetrical pedal is the same spindle that is being used in conventional bicycle pedals, to mount the conventional pedals on the crank arm of conventional bicycles and it is marked 4. The portion of this pedal from the spindle to the front foot rest is referred to as the front end of this pedal and the portion from the spindle to the rear foot rest is referred to as the back end of this pedal. The length of the front end of this pedal is longer than the length of the back end and that is how this pedal becomes asymmetrical. The length of the front end of this asymmetrical pedal must allow the free movement of the front wheel of the vehicle on which it is mounted, while negotiating turnings on the road. The length of the back end should be sufficient to place the rear footrest below the heel of the rider while the ball of the foot of the rider is placed above the front footrest. A tube within which a spring loaded protruding rod is placed is marked 5. The outer diameter of both the ends of this tube is less than the outer diameter of the remaining section of this tube. The length of the end of this tube with smaller outer diameter, that is to be mounted on the side of the pedal near the crank arm must be equal to the thickness of the frame of the pedal, and the length required to hold a nut marked 6 on that end. The protrusion of the tube with smaller outer diameter, outside the frame at this end is threaded and when the nut marked 6 is tightened on this threaded end, this end of the tube will get tightly secured to the frame of the pedal. The length of the other end of the tube with smaller outer diameter must be equal to the thickness of the frame of the pedal. The inner side of the tube at this end is threaded to receive a bolt marked 7 and when this bolt is tightened on to the tube, the tube will get tightly secured to the frame of the pedal at this end also. A spring loaded protruding rod is marked 8. The diameter of this rod must be sufficient to withstand the forces it will be subjected to and to allow it's free in and out movement inside the tube marked 5. This rod protrudes from the outer face of the pedal frame near the crank arm. The maximum protrusion of this rod is the length required to reach under the crank arm. The surface of this rod coming in contact with the crank arm while the rod is beneath the crank arm is straight and all the other sides of the protrusion are formed in a slanting shape. A helical spring marked 9 is placed in between the rod marked 8 and the bolt marked 7. The ends of the rod and the bolt are shaped to hold the helical spring marked 9 in proper place to facilitate the in and out movement of the rod. The clearance between the rod marked 8 and the bolt marked 7 shall be sufficient to accommodate the inward movement of the rod marked 8 and the compressed length of the helical spring marked 9. There is a longitudinal groove marked 10 on the rod marked 8. A smaJI screw marked 11 is driven through the tube and its tip is long enough to reach inside the groove marked 10. This screw limits the outward movement of the rod marked 8.The length, width and depth of the groove shall be just sufficient to allow the free in and out movement of the rod marked 8, wbHe the tip of the screw marked 11 is positioned inside the groove. The positioning of the groove marked 10 and the screw marked 11 should bring the protruding end of the rod marked 8 to its correct alignment and position to restrict the forward rotation of the pedal, when the protruding rod is pushed out of the tube marked 5 by the helical spring marked 9. Various types of screws, nuts and bolts, washers, etc. that are required for mounting and anchoring all the parts on the frame of this pedal has to be used and those are not shown in the drawings. The back end of this asymmetrical pedal is made heavier than the front end of the pedal. So, while idle, this pedal will remain in vertical alignment with the short back end at bottom, leaving almost the same clearance between the pedal and ground as in the case of conventional pedals. The relative position of the protruding rod; to the spindle of this asymmetrical pedal is very crucial because while riding, this relative position decides the beginning and end of the arc through which the indirect enhancement of the crank arm will exist during rotary motion of the crank arm. Ideally, a larger segment of the said arc should be above the horizontal position of the crank arm in the forward semicircle of the rotary motion of the crank arm. Because, while the pedal is above the horizontal position of the crank arm, the foot of the rider will be in a flexed up alignment, and while the pedal is below the horizontal position of the crank arm, the foot of the rider will be in a flexed down alignment and in the flexed up alignment of the foot, the rider will be able to apply force more efficiently on the front footrest with the ball of the foot, than with the foot in a flexed down alignment. If the upper end of the said arc is shifted higher, to a position beyond a certain limit, then also the efficiency to deliver force on the front footrest will decrease. The difference in height of the front footrest and the rear footrest also influence the position of the arc through which the indirect enhancement of the crank arm will exist. So by adjusting the difference in height of the footrests and the relative position of the protruding rod to the spindle of this pedal, a desirable position for the top end of the said arc can be fixed. The most desirable position for the top end of the said arc will be at an angle between thirty five degrees and forty five degrees above the horizontal plane passing through the axis of the crank arm about which the crank arm rotates, and in the top half of the front semicircle of the rotary motion of the crank arm. The primary function of the front footrest is to position the point of delivery of force by the foot, to the very edge of the front end of this asymmetrical pedal so that maximum possible torque will be generated for any given force applied by the foot of a rider. During pedaling, while the pedal and crank arm are in the rear semicircle of the rotary motion of the crank arm, the protruding rod will be away from the crank arm. Once the crank arm and pedal pass the top position of the rotary motion of the crank arm, the protruding rod move closer to the crank arm and at a certain position, the protruding rod will get pressed against the crank arm on the top side of the crank arm and as the rotation continues, the crank arm with the help of the slanting shape of the protruding rod will push the protruding rod into the tube and disengage it from the crank arm. As the rotation of the crank arm continues further, the tip of the protruding rod will be pressed against the vertical face of the crank arm near the pedal and as the tip of the protruding rod pass the bottom of the vertical face of the crank arm the spring inside the tube will push the rod out and the straight portion of the rod will come in contact with the crank arm at the bottom side of the crank arm. This will arrest the forward rotation of the pedal about the axis of its spindle. In this condition the length of the crank arm will get indirectly extended by the distance from the axis of the spindle of the pedal to the front foot rest of the pedal. This extension will continue to exist until the contact between the crank arm and protruding rod gets separated during the continuous rotation of the crank arm and pedal. This process will continue during each rotation of the crank arm and will enhance the torque at the most advantageous position of the crank arm to convert the force applied on the pedal into torque of the mechanism during the rotary motion of the crank arm. In all other positions of the pedal and crank arm, this pedal will function just like a conventional pedal.The enhanced torque produced by this pedal can be used to enhance the load carrying capacity of the vehicle or to increase the speed of the vehicle with the help of step up gears as is being done in conventional multi gear bicycles.