Patent Publication Number: US-2011068554-A1

Title: Non-motorized vehicle

Description:
This application is a continuation of U.S. application Ser. No. 12/367,926, tiled Feb. 9, 2009, which claims the benefit of U.S. Provisional Application No. 61/027,302, filed Feb. 8, 2008, the disclosures of which are hereby incorporated by reference in their entireties. This application is related to U.S. Design Patent Application No. 29/299,331, filed Dec. 21, 2007. 
    
    
     FIELD OF THE INVENTION 
     The invention described herein relates generally to non-motorized vehicles. More specifically, the invention described herein relates to non-motorized foot board scooters having a kick arm for rider-generated propulsion of the scooter. 
     BACKGROUND 
     Non-motorized foot board scooters are known in the art. These scooters generally include a front wheel aligned with a back wheel, with each of the wheels being attached to a frame. The frame generally comprises a flat surface located between the two wheels for the rider to stand on and a steering column rising vertically from the front end of the flat surface, The steering column is attached at one end to the front wheel for front wheel steering of the scooter and terminates at the other end in handle bars for the rider to use to steer the scooter. Forward movement of these non-motorized foot board scooters is normally achieved by the rider taking one foot off the flat surface and pushing against the ground with the foot removed from the flat surface to begin forward movement of the scooter. 
     In some non-motorized foot board scooters known in the art, an improved means for propelling the scooter forward is included. For example, as shown in U.S. Pat. No. 6,857,648, depression of a pedal located on the foot board of the scooter causes gears and chains located under the foot board to turn. The chains are connected to the back wheel of the scooter, and therefore movement of the chains cause the back wheel to turn and propel the scooter forward. However, the size and placement of the pedal in the &#39;648 patent limit the downward force the rider can apply and also the speed at which the pedal can be depressed. These limitations limit the ability of the rider to generate speed. 
     Accordingly, there exists a need for an improved non-motorized foot board scooter having a human-generated propulsion mechanism for propelling the scooter forward. 
     SUMMARY 
     Described herein are various embodiments of a non-motorized foot board scooter that overcome many of the disadvantages and shortcomings of conventional non-motorized foot board scooters. 
     Generally, the non-motorized foot board scooter comprises a frame, a steering column, a foot board, a drive train housing, a drive train, a front wheel and a rear wheel. The drive train includes a kick arm that rotates the rear wheel when the kick arm is pushed backwards by the rider. The kick arm is centered with the rear wheel and is curved in a manner that mimics the curvature of the rear wheel. The drive train housing includes a kick guard located over a portion of the rear wheel. Braking of the scooter is achieved via a band brake or friction brake located on the rear wheel. 
     The frame may be an elongate frame having a length and a width. The kick guard may be located between the kick arm and the rear wheel. A steering assembly may be pivotably disposed on the frame, which could include a front wheel and handlebars. 
     The drive train may including an arm rotatably disposed on the frame and extending upwardly from the center of the width of the frame, A first sprocket is mounted to the arm and may be offset to the side of the arm or from the center of the frame. The rear wheel or drive wheel has an associated second sprocket that may be connected to the rear wheel via a clutch or free-wheel. The clutch may be a one way bearing such as a one way needle bearing. 
     A chain including a first end portion is mounted to the frame at a first location and extends around the first and second sprockets. The chain includes a second end portion mounted to the frame at a second location. The chain is routed such that as the arm is rotated the chain is drawn across the second sprocket thereby rotating the drive wheel. The chain may also extend around a pulley wherein the pulley is resiliently biased against the chain, such as by a spring. 
     In one embodiment the first sprocket includes a plurality of teeth disposed about a first axis and is rotatably mounted to the arm about a second axis that is offset from the first axis. Furthermore, each of the plurality of teeth may be disposed equidistant from the first axis. Also, the second end portion of the chain may be secured to a movable mount, whereby movement of the movable mount causes the first sprocket to rotate independently of the arm. The vehicle may also include a hand lever mounted on the handlebars and a cable connected between the hand lever and the movable mount. Movement of the hand lever causes the movable mount to change positions thereby rotating the first sprocket independently of the arm. 
     The foregoing and other features, utilities, and advantages of the foot-board scooter will be apparent from the following more particular description of the embodiments as illustrated in the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate multiple embodiments of a foot-board scooter and together with the description, serve to explain the principles thereof. Like items in the drawings are generally referred to using the same numerical reference. 
         FIG. 1  is a perspective view of a scooter according to a first exemplary embodiment; 
         FIG. 2  is a left side elevation view thereof; 
         FIG. 3  is a front side elevation view thereof; 
         FIG. 4  is a top plan view thereof; 
         FIG. 5  is a right side elevation view thereof; 
         FIG. 6  is a bottom plan view thereof; 
         FIG. 7  is a cross-sectional view of the band brake system employed on the scooter shown in  FIGS. 1-6 ; 
         FIG. 8  is a partial simplified cross-sectional view illustrating the drive train system as shown in  FIGS. 1-7 ; 
         FIG. 9  is a simplified cross-sectional view of the rear wheel taken about line  9 - 9  as shown in  FIG. 8 ; 
         FIG. 10  is a simplified cross-sectional view of a. drive train system employed in a second exemplary embodiment of a scooter; 
         FIG. 11A  is an enlarged partial view illustrating the cam sprocket shown in  FIG. 10 ; 
         FIG. 11B  is an enlarged partial view similar to  FIG. 11A  with the cam sprocket rotated; and 
         FIG. 11C  is an enlarged partial view similar to  FIGS. 11A and 11B  with e cam sprocket rotated still further. 
     
    
    
     DETAILED DESCRIPTION 
     In one embodiment of the present invention, a non-motorized foot board scooter having a mechanism for providing rider-generated propulsion of the scooter is disclosed. As shown in  FIG. 1 , the scooter  10  generally comprises a frame  20 , a steering column  30 , a foot board  40 , a drive train housing  50 , a front wheel  60 , a rear wheel  70  and a drive train  80 . 
     As shown in  FIG. 2 , the frame  20  generally comprises a steering column receiving portion  22 , a bridge portion  24  and a foot board supporting potion  26 . 
     The steering wheel column receiving portion  22  generally comprises a hollow cylinder through which the steering column  30  passes. The steering wheel column receiving portion  22  has an inner diameter approximately equal to the outer diameter of the steering column  30 . The steering wheel column receiving portion  22  may also have a clamp  28  at the top end. When the clamp  28  is closed, the steering wheel column  30  is fixed in place and cannot slide up or down in the hollow cylinder. When the clamp  28  is open, the steering wheel column  30  may move up and down in the hollow cylinder. In this manner, the steering wheel column may be folded down to make the scooter  10  more compact. 
     The bridge portion  24  of the frame  20  connects the steering wheel column receiving portion  22  to the foot board supporting portion  26  of the frame  20 . The bridge portion  24  may have a variety of shapes. In  FIG. 2 , the shape of the bridge portion  24  is predominantly rectangular and straight. However, the bridge portion  24  may also be curved or have any other suitable shape. Bridge portion  24  may be pivotably connected to either steering column  30  or foot board supporting portion  26  to collapsing the frame for storage or the like. 
     The foot board supporting portion provides a platform on which the foot board  40  may be placed. As shown in  FIG. 2 , the foot board supporting portion  26  also may be used as a housing for a portion of the drive shaft  80  and the brake line or cable  39  extending between the hand brake on the handle bar and the rear wheel  70 . As with the bridge portion  24 , the foot board may have any suitable shape. Preferably and as shown in  FIG. 2 , the foot board supporting portion  26  is aligned parallel to the ground so as to maintain a clearance between the scooter  10  and the ground. 
     The material of the frame  20 , including the steering column receiving portion  22 , the bridge portion  24  and the foot board support portion  26  may be any suitable material, such as metal or a durable plastic. 
     As shown in  FIG. 3 , the steering column  30  generally comprises a cylindrical body  31  having a top end  32  and a bottom end  33 , a fork  34  coupled to the bottom end  33  for receiving the front wheel  60  and a handle bar  35  located at the top end  32 . 
     As noted earlier, the cylindrical body  31  has an outer diameter approximately equal to the inner r of the steering wheel column receiving portion  22 . 
     A fork  34  is located at the bottom end  33  of the cylindrical body  31 . The space between the two prongs of the fork  34  is slightly larger than the width of the front wheel  60  so that the front wheel  60  does not rub against the fork  34  when in motion. Similarly, the length of the inside surface of the two prongs of the fork  34  is slightly larger than the radius of the front wheel  60  so the front wheel  60  may rotate freely. The terminal ends of the prongs of the fork  34  include a means for coupling to the front wheel  60  in manner that allows the front wheel  60  to rotate. For example, a. rod or axle may extend between the terminal ends of the prongs of the fork  34  and pass through a center hole in the front wheel  60 . 
     Handle bar  35  is located at the top end  32  of the cylindrical body  31 . As shown in  FIG. 3 , the handle bar  35  may be coupled to the cylindrical body via a clamp  36 . Any other suitable means of coupling the handle bar  35  to the cylindrical body  31  also may be employed. As shown in  FIG. 3 , the handle bar  31  is oriented perpendicularly to the cylindrical body  31 . In  FIG. 3 , the handle bar  31  is straight, although in other aspects of the embodiment, the handle bar  31  may have curves or bends. Handle bar grips  37 , made from any suitable material and having any suitable shape, may be placed at both ends of the handle bar  35 . Additionally, a hand brake  38  may be placed on the handle bar  35 . While only one hand brake  38  is illustrated in  FIG. 3 , a second hand brake may also be located on the handle bar  35 . The hand brake  38  is connected to the braking mechanism, discussed in greater detail below, via the brake cable  39 . The brake cable  39  may be coupled to the cylindrical body  31  at various points to keep the brake cable  39  from getting tangled, and as mentioned previously, the brake cable  39  may run through the foot board support portion  26  on its way to the brake mechanism on the rear wheel  70 . 
     The material of the steering column  30 , including the cylindrical body  31 , the fork  34  and handle bar  35 , may be any suitable material, including metal or durable plastic. 
     As shown in  FIG. 4 , the foot board  40  generally comprises an elongated flat surface on which the rider may stand. While  FIG. 4  illustrates a foot board having a generally rectangular shape with rounded corners, any suitable shape for the foot board may be used. The width of the foot board  40  is preferably such that both feet of a rider may fit on the foot board  40  whether the rider&#39;s feet are aligned in parallel with the foot board  40  or perpendicularly to the foot board  40 . The surface of the foot board  40  may have treads, a rough surface or any other means for preventing slipping on the foot board. Additionally, holes  42  may be formed in the foot board  40  to prevent water from collecting on the foot board  40 . The material of the foot board  40  may be any suitable material, such as metal or durable plastic. 
     As shown in  FIG. 5 , a drive train housing  50  is located at the rear end of the scooter  10 . The drive train housing  50  extends away from the foot board  40  and is generally oriented parallel to the ground. The drive train housing  50  is coupled to the foot board  40  using any suitable means, such as by welding. 
     Drive train housing  50  generally comprises a right side plate  52 , a left side plate (not shown) and a top plate  54 . The right side plate  52  and left side plate are aligned parallel to each other and perpendicular to the foot board  40 . A space is maintained between the right side plate  52  and left side plate such that the drive train  80  and rear wheel  70  will fit between and be protected by the two plates. As shown in  FIG. 5 , the height of the right side plate  52  increases as the right side plate extends away from the foot board  40  in order to cover and protect the sides of the rear wheel  70 . Right side plate  52  and left side plate also include a rear wheel securing portion  53 . The rear wheel securing portion  53  generally comprises a rod or axle extending between the right side plate  52  and left side plate and which passes through the rear wheel  70  centered between the right side plate  52  and left side plate. The axle also may pass through and hold in position the brake and portions of the drive train discussed in greater detail below. As shown in  FIG. 5 , the rear wheel securing portion  53  is secured to the right side plate  52  and left side plate via a series of bolts that pass through a face plate to which the rod is coupled and the right side plate  52  or left side plate. 
     The left side plate not shown in  FIG. 5  is a mirror image of right side plate  52  and is therefore essentially as described above. As shown in  FIG. 5 , left side plate does differ from right side plate  52  in that a kick stand  58  is coupled to left side plate. The kick stand  58  may be any kick stand known in the art, and as shown in  FIG. 5 , the kick stand  58  may include a spring for retracting the kick stand  58  when not in use. While the kick stand  58  is shown on the left side plate in  FIG. 5 , the kick stand  58  could also be located on the right side plate  52  or in any other suitable location along the scooter  10 . 
     The right side plate  52  and left side plate are coupled together at a portion of their top edges by the top plate  54 . The top plate  54  is generally aligned perpendicularly to the right side plate  52  and left side plate and in parallel to the foot board  40 , A gap exists between the rear end of the foot board  40  and the front end of the top plate  54  such that the top plate  54  does not directly contact the foot board  40 . That is to say, the foot board  40  is coupled to the drive train housing  50  only at the right side plate  52  and left side plate. The gap between the foot board  40  and the top plate  54  serves as the area. through which a kick arm of the drive train, as described in greater detail below, may pass. Additionally, the top plate  54  does not extend back the entire length of the right side plate  52  and left side plate. In this manner, a rear wheel  70  may be centered between the right side plate  52  and left side plate at the rear portion of the drive train housing  50  and extend above the right side plate  52  and left side plate. 
     The top plate  54  includes a kick guard  56  extending away from the rear portion of the top plate  54  and inclining upwardly in a curved fashion that follows the shape of the rear wheel  70 . The kick guard  56  only extends from the center of the rear of the top plate  54  and therefore does not have a. width equal to the gap between the right side plate  52  and left side plate. Rather, the width of the kick guard  56  is approximately equal to the width of the rear wheel  70 . The length of the kick guard  56  is from the rear portion of the top plate  54  to its termination point at approximately the apex of the curve, i.e., before the curve begins to take a downward turn. The center portion of the top plate  54  from which the kick guard  56  extends is aligned with the centered position of the rear wheel  70  in the drive train housing  50 . As mentioned above, the curvature of the kick guard  56  generally mimics the radius of curvature of the rear wheel  70 . The kick guard  56  is positioned such that the curved kick guard  56  sits slightly above the rear wheel  70  without contacting the rear wheel  70 . Given the above description of the shape and positioning of the kick guard  56 , it is apparent that the kick guard  56  protects the rear wheel  70  from being contacted by the rider or the kick arm, and thereby increases the safety of the scooter. The top plate  54  and kick guard  56  also may be shaped differently than as described above to accomplish the same objective. 
     The material of the drive train housing, including the left side plate, right side plate, top plate and kick guard, may be any suitable material, such as metal or durable plastic, 
     As mentioned above, the scooter includes a front wheel  60  and a rear wheel  70 . As shown in  FIG. 6 , the front wheel  60  is positioned between the fork  34  and the rear wheel  70  is positioned between the left side plate and right side plate  52  of the drive train housing  50 . Both the front wheel  60  and the rear wheel  70  are mounted to the scooter in a manner that allows for free forward rotation of the wheels. 
     As shown in  FIG. 6 , front wheel  60  is larger in diameter than rear wheel  70 , while both wheels have the same width. However, the front wheel  60  may have a diameter smaller than or equal to the diameter of the rear wheel  70 . The front wheel  60  may also have a larger or smaller width than the rear wheel  70 . The material of either the front wheel  60  or rear wheel  70  is not limited. Any suitable material may be used, such as rubber or plastic. 
     The rear wheel  70  may include a brake  72 . In the presently described invention, the brake is a band brake. A band brake as used in the present invention as illustrated in  FIG. 7 . A central portion or drum  73  of the rear wheel  70  extends out from the rear wheel perpendicularly to provide an area around which the band  74  may wrap. A first end  75  of the band  74  is secured to an anchor  76  that does not move. The second end  77  of the band  74  is secured to one arm  78 A of a pivoting member  78  that pivots about point A. A second arm  78 B of the pivoting member  78  is secured to the brake cable  39  described above in relation to the steering column  30  shown in  FIG. 3 . In a non-braking position, the band  74  is slack around the central portion  73  as shown in  FIG. 7 . When the rider grips the hand brake  38  illustrated in  FIG. 3 , the brake cable  39  is pulled taught, causing the pivoting portion  78  to pivot about point A due to the attachment of brake cable  39  to second arm  78 B. This in turn causes the first arm  78 A to move and pull band  74  taught against the central portion  73 . Any rotation of the drum  73  (i.e., rotation of the rear wheel  70 ) is slowed or stopped due to the friction between the band  74  and the drum  73 . Band  74  and drum  73  therefore each preferably have high friction surfaces so that the rotating drum  73  does not slip against the band  74  when the band is pulled taught around the central portion  73 . 
     As shown in, for example,  FIG. 4 , the scooter  10  includes a brake  72  only on the rear wheel  70 . However, as discussed above, the scooter  10  may have a second hand brake lever on the handle bar  35 . The second hand brake lever may, for example, be connected to a band brake or other style of brake, such as a caliper, or disc brake located in relation to front wheel  60  of the scooter  10 . 
     The drive train  80  is the mechanism for allowing the rider of the scooter  10  to propel the scooter forward without having to take one foot off the foot board and push against the ground. The drive train  80  is illustrated in  FIG. 8 . The drive train generally includes first pulley  81 , first sprocket  82 , second sprocket  83 , second pulley  84 , chain  85 , spring  86 , first chain anchor point  87 , second chain anchor point  88 , spring anchor point  89 , and kick arm  90 . 
     In operation, the drive train works by pushing back on kick arm  90  causing first sprocket  82  to move forward thus pulling chain  85  across second sprocket  83 . Movement of chain  85  across second sprocket  83  causes it to rotate, Second sprocket  83  is coupled to axle  92  which is in turn attached to rear wheel  70 . Accordingly, pushing back on kick arm  90  causes rear wheel  70  to rotate and propel the scooter forward. 
     Kick arm  90  of drive train  80  is a relatively thin bar that extends vertically from its connection point with the drive train  80  to a position above the foot board. As noted previously, a gap between the rear end of the foot board  40  and the top plate  54  of the drive train housing  50  is provided for the kick arm to extend up and out of the drive train housing  50 . Advantageously, kick arm  90  protrudes from the drive train housing  50  in the center of the width of the scooter, 
     A foot bar  91  is located at the top end of the kick arm  90 . The foot bar  91  is aligned perpendicularly to the kick arm  90 . The foot bar  91  connects with the kick arm  90  in the middle of the foot bar  91  such that the foot bar  91  extends equally to the left and right of the kick arm  90 . Accordingly, given the placement of the kick arm  90  in the center of the width of the scooter and the foot bar  91  which extends to both the left and right of the kick arm  90 , a rider of the scooter may easily push down on the kick arm  90  via the foot bar  91  with either their left or right foot. Furthermore, because kick arm  90  is located along the center line of the scooter, the force applied to the kick arm is directed along the center of the scooter, thereby reducing the amount of torque generated between the handle bars and kick arm. 
       FIG. 8  also illustrates that the kick arm  90  has a curvature rather than being a perfectly straight bar. As with the kick guard  56 , the curvature of the kick arm  90  has a curve that resembles the curve of the rear wheel  70 . By providing the kick arm  90  with a curvature that resembles the curvature of the rear wheel  70  and kick guard  56 , the rider will be able to push the kick arm  90  down further than would be possible if the kick arm were straight and is thereby able to generate more forward propulsion of the scooter via the drive train. If the kick arm were straight, the lower portion of the kick arm would come into contact with the kick guard  56  earlier than if the kick guard has a curvature. The curvature of the kick arm  90  means that the lower portion of the kick arm  90  will curve around the kick guard  56  and allow for further backward movement of the kick arm  90 . 
     The kick arm  90  pivots about pivot point B shown in  FIG. 8 . Pivot point  13  may be, for example, a rod extending between the left side wall and right side wall  52  of the drive train housing  50  or a rod that extends between a small housing included at the rear portion of the foot board  40 , wherein the rod also passes through a hole in the kick arm  90 . When the kick arm is pushed backward as show by arrow  100 , the first sprocket  82  coupled to the bottom end of the kick arm  90  moves in the direction indicated by arrow  102 . The first sprocket  82  is coupled to the bottom end of the kick arm  90  in a manner which allows the first sprocket  82  to freely rotate. Therefore, as the first sprocket  82  is moved in the direction of arrow  102 , the first sprocket  82  rotates, grips the chain  85  and passes the chain  85  around the first sprocket  82 . 
     Chain  85  is anchored at one end at first chain anchor point  87  and at a second end at second chain anchor point  88 . First chain anchor point  87  and second chain anchor point  88  may be, for example, tabs that extend from the foot board supporting portion  26  and the left side wall or right side wall  52  of the drive train housing  50  and the chain  85  may be coupled to the anchor portions by any suitable means. Because the chain  85  is anchored at first chain anchor point  87  and second chain anchor point  88 , movement of the first sprocket  82  as discussed above must be accompanied by movement of another component of the drive train to allow for movement of the chain  85 . Accordingly, first pulley  81  is attached to spring  86 . The spring  86  and first pulley  81  may be coupled by, for example, a hook extending from the end of the spring and hooking through a hole in the middle of the first pulley  81 . Similarly, the spring  86  may be anchored to a portion of the frame  20  via a hook extending from the opposite end of the spring and hooking through a hole in a portion of the frame  20 . 
     When the kick arm  90  is pushed hack, causing the first sprocket  82  to move in the direction of arrow  102 , spring  86  extends to allow first pulley  81  to move in the direction indicated by arrow  104 . The chain  85  rotates around the first pulley  81  and thereby provides slack for the first sprocket  82  to take up when moving the chain  85  around the first sprocket  82 . In this manner, the chain  85  anchored at both ends is capable of moving and causing second sprocket  83  and second pulley  84 , which are stationary, to rotate. 
     As noted above, movement of first pulley  81  and first sprocket  82  and the corresponding movement of chain  85  causes rotation of the second sprocket  83  and the second pulley  84 . 
     Unlike first pulley  81  and first sprocket  82 , second pulley  84  only rotates about a stationary axis. Thus, when the chain  85  moves past second sprocket  83  and second pulley  84  due to movement of first pulley  81  and first sprocket  82 , second pulley  84  rotate about its axis. 
     The axis about which second pulley  84  rotates may be a rod coupled to an inside side wall of the drive train housing  50 . The rod for the second pulley  84  is stationary; therefore the second pulley  84  rotates about the rod without the rod rotating. The direction of rotation of second pulley  84  is indicated by arrow  106 . 
     When the kick arm  90  is fully pushed back, the first sprocket  82  is pushed in the direction of arrow  102  to its fullest extent and first pulley  81  is pulled against spring  86  in the direction of arrow  104  to its fullest extent. Spring  86  is fully extended when the kick arm  90  is fully pushed back. Accordingly, when pressure is no longer applied on the kick arm in its fully pushed back position, the spring  86  under tension recoils to pull the first pulley  81  back to its resting position, which in turn causes first sprocket  82  to return to its resting position and kick arm  90  to return to its resting position. In this manner, kick arm  90  remains in the resting position whenever force is not applied thereto and kick arm  90  always returns to its resting position when force previously applied to the kick arm  90  is removed. Restoring the drive train  80  to the resting position causes all components of the drive train  80  to rotate in the opposite direction of the direction the components rotated when force is applied to the kick arm  90 . 
     However, when force is no longer applied to the kick arm  90  and the drive train  80  operates in reverse to return to resting position, the rear wheel  70  will not rotate in reverse because of the free-wheel interface between sprocket  83  and axle  92 . In this case, the free-wheel or clutch arrangement comprises a one-way needle bearing  93  (see  FIG. 9 ). Bearing  93  is disposed between sprocket  83  and axle  92 . As sprocket  83  rotates forward (in the direction of arrow  108 ) one-way needle bearing  93  engages axle  92  thus rotating the axle and driving the scooter forward. However, when sprocket  83  begins to rotate in reverse as the drive train  80  reverts back to its resting position, one-way needle bearing  93  disengages from axle  92  thus allowing the wheel to freely rotate independent of the rotation of sprocket  83 . 
       FIG. 9  is a cross-section of rear wheel  70  with the brake band and housing as well as the drive train housing not shown for clarity, it can be appreciated that wheel  70  is affixed to axle  92 . Axle  92  in turn rotates in bearings  94 ( 1 ) and  94 ( 2 ), which are mounted to housing  50 . Brake drum  73  is also affixed to wheel  70 . Thus, it can be appreciated that wheel  70 , axle  92  and brake hub  73  all rotate together in bearings  94 ( 1 ) and  94 ( 2 ). Bearings  94  can be any suitable bearing such as a ball bearing or roller bearing. Also, shown in  FIG. 9  is sprocket  83  mated with one-way bearing  93 . In this case, one way bearing  93  is a needle bearing. It should be understood that other one way bearings may be utilized as well as pawl and ratchet arrangements commonly used on bicycles. A spacer  95  may be disposed between sprocket  83  and the hub portion of wheel  70  to control the location of sprocket  83  relative to the rest of the drive train components, 
     A second exemplary embodiment of a scooter drive train  280  is illustrated in  FIG. 10 . Drive train  280  is similar to that described above with respect to the first exemplary embodiment. In this embodiment, however, the first sprocket is replaced with a cam sprocket  282  that is pivotally mounted about pivot pin  297  offset from its center. With further reference to  FIGS. 11A-11C , it can be appreciated that as kick arm  290  is pushed back about pivot B, cam sprocket  282  rotates in a counter-clockwise direction. As cam sprocket  282  rotates the effective diameter of the sprocket changes in relation to chain  285  (shown schematically for clarity). Thus, cam sprocket  282  provides a cam effect. The cam effect may be varied by rotating the starting position of the cam sprocket  282 . For instance, in  FIG. 11A , the sprocket is positioned to provide the least resistance to rotation. At this point the distance “d” between pivot  297  and the tangent point of chain  285  is at its minimum. On the other hand, as shown in  FIG. 11C , distance “d” is approaching its maximum. When “d” is at its maximum, resistance to rotation is greatest. it should be appreciated that as the resistance to rotation varies, the rate at which chain  285  is pulled across sprocket  283  varies accordingly. 
     As shown in  FIG. 10 , the position of the second anchor point of chain  285  may be varied with anchor lever  288 , which rotates about an anchor pivot C. As anchor cable  296  is pulled cam sprocket  282  rotates counterclockwise, thereby changing the starting position of cam sprocket  282  without moving kick arm  290 . Cable  296  may be pulled using a hand lever arrangement similar to that described above with respect to the brake mechanism. In use, a rider could start with anchor lever  288  in a starting position as shown in  FIG. 10 , wherein cam sprocket  282  is in a minimum resistance position, such as shown in  FIG. 11A , This allows the rider to propel the scooter from a stop or up a hill with less initial effort. As the rider propels the scooter, cable  296  may be pulled thereby rotating the cam sprocket&#39;s starting position toward the maximum resistance position thus providing more propulsion as the scooter increases in speed. Once cable  296  is released, spring  286  acts to return anchor lever  288  to the starting position. 
     While the exemplary embodiments have been described to utilize chain and sprockets, other elongate flexible tension members and their corresponding pulleys and sheaves are contemplated. For example, suitable timing belts and timing pulleys should be considered equivalent to a chains and sprockets. 
     Accordingly, the foot board scooter has been described with some degree of particularity directed to the exemplary embodiments. It should be appreciated, though, that the present invention is defined by the following claims construed in light of the prior art so that modifications or changes may be made to the exemplary embodiments without departing from the inventive concepts contained herein.