Abstract:
A front wheel of a scooter is pivotally mounted to a frame and includes an upwardly extending shaft supporting a handlebar for steering the scooter. A footpad or peg or pedal, mounted on a spring returned lever, is interconnected with the rear wheel through a gear mechanism supported by the frame. By pumping the footpad, rotation of the rear wheel and forward motion of the scooter occurs. The gear mechanism includes a first gear or sprocket mounted for rotation about the arms of rotation of the rear wheel. A further sprocket coaxially mounted is linked via a drive-chain to a sprocket on an offset shaft. A further sprocket on the offset shaft drives a final, drive sprocket via a further chain. And the final sprocket drives the rear wheel through a one way clutch. Depression of the footpad, peg or pedal moves a rack-like bar longitudinally. The bar is in engagement with and drives the first gear or sprocket. The bar may carry drive-chain cross-members or pins that engage the teeth of the first sprocket.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is directed to subject matter disclosed in and claims priority to a first provisional application entitled “FOOT-PUMP SCOOTER”, filed May 1, 2001 and assigned Serial No. 60/287,839 and a second provisional application entitled “PUMP SCOOTER”, filed Sep. 7, 2001 and assigned Serial No. 60/318,192. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to scooters and, more particularly, to scooters propelled forwardly by a rider operated pivotally mounted lever. 
     2. Description of Related Art 
     Conventional scooters are propelled forwardly by a rider having one foot on a platform between the front and rear wheels and pushing rearwardly against the ground with the other foot. Such scooters are speed limited on a flat surface by the speed and power of the rider pushing rearwardly against the ground. Because of the physical effort required, scooters of this type are relatively slow and higher speeds are possible only for short periods of time. 
     To increase the sustainable duration at higher speed, various foot operated motive mechanisms have been developed. One type of mechanism includes a foot operated lever repetitively drawing a chain in contact with a sprocket secured to the rear wheel through a one way clutch. In another type of self propelled scooter, a pair of footpads or pegs are pumped by the rider&#39;s feet, which pumping motion is translated to rotary motion of the rear wheel. These mechanisms overcome the need to repeatedly push against the ground with one of the rider&#39;s feet but various detrimental aspects exist. For example, the resulting speed of the scooter is little more, if any, beyond that of a conventional scooter wherein the same amount of effort is applied. The dual foot pedal arrangement negates the existence of a solid platform upon which a rider may rest his feet as he wishes. Certain of the mechanisms are complex, expensive and of limited life in the environment within which a scooter is expected to be used by a child or young adult. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a scooter mechanically propelled by a rider and having a front wheel steerable through the handlebar. A spring returned arcuate lever is repetitively depressed by a rider&#39;s foot. The resulting movement of the lever rotates an engaged initial sprocket mounted on a shaft common with the rear wheel. The initial sprocket includes a one way clutch to permit return of the lever. A gear mechanism interconnects the initial sprocket with a final sprocket mounted on the shaft and keyed with the rear wheel. The final sprocket may include a one way clutch to permit freewheeling of the rear wheel. By selecting a gear ratio of the gear mechanism commensurate with the strength and weight of the rider, a significantly increased forward speed over that of a conventional foot powered scooter can be achieved. 
     It is therefore a primary object of the present invention to provide a foot operated mechanism for a scooter to compel forward motion. 
     Another object of the present invention is to provide a lever operated gear mechanism for propelling a scooter. 
     Yet another object of the present invention is to provide a simple foot operated gear mechanism for propelling a scooter. 
     Still another object of the present invention is to provide a foot operated gear mechanism adapted for use within the normal environment of a scooter without significant danger of jamming or breakdown. 
     A further object of the present invention is to provide a relatively inexpensive and easily repairable foot operated gear mechanism for propelling a scooter. 
     A yet further object of the present invention is to provide a foot operated gear mechanism intermittently actuated to permit a rider to rest while the scooter coasts. 
     A still further object of the present invention is to provide a method for propelling a scooter by a foot operated pumping action. 
     These and other objects of the present invention will become apparent to those skilled in the art as the description of the invention proceeds. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention maybe described with greater specificity and clarity with reference to the following drawings, in which: 
     FIG. 1 illustrates a perspective view of a foot operated gear mechanism mounted on a scooter; 
     FIG. 2 is a cross sectional view taken along lines  2 — 2 , as shown in FIG. 1; 
     FIG. 3 is a partial side view of the final stage of the gear mechanism; 
     FIG. 4 is an exploded view of the gear mechanism; 
     FIG. 5 illustrates the movement of the foot operated lever; 
     FIGS. 6 a  and  6   b  illustrate the support structure for the gear mechanism; 
     FIG. 7 illustrates the common axis of the initial and final sprockets of the gear mechanism; 
     FIG. 8 illustrates a first side view of a variant gear mechanism; 
     FIG. 9 illustrates another side view of the variant gear mechanism; 
     FIG. 10 illustrates a gear mechanism mounted at the front of the scooter for driving the rear wheel; and 
     FIG. 11 illustrates a further view of the front mounted gear mechanism. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 1, there is shown a perspective view of a foot pump scooter  10  embodying the present invention. A front wheel assembly  12  is rotatably mounted within a fork  14  depending from a shaft  16  rotatably mounted in a sleeve  18  or the like secured to the front of frame  20 . A handlebar  22  is attached at the upper end of shaft  16  and may include handgrips  24 ,  26 . A caliper brake assembly  28  may be mounted on fork  14  to provide a braking function for wheel  30  of the front wheel assembly. A manually operated brake handle  32  mounted upon handlebar  22  actuates the caliper brake assembly through a sheathed cable  34 . 
     Frame  20  of foot pump scooter  10  includes a platform  40  upon which a rider may place one or both of his feet. A spring loaded kickstand  42  may be attached to the frame to permit parking the foot pump scooter in an upright orientation. 
     Referring jointly to FIGS. 1,  2 ,  3 ,  4 ,  5  and  7 , details of the rear wheel assembly, it&#39;s mounting and the associated gear mechanism will be described. A pair of ears  44 ,  46  are secured to and extend upwardly from longerons  48 ,  50  of frame  20  to support and retain axle  52 . The ears may include forwardly oriented slots to accommodate removal of the wheel assembly and to adjust the tension of the chains of the gear mechanism. The wheel mechanism includes a wheel  54  and hub  55  rotatably mounted upon axle  52 . A final sprocket  56  is attached to the wheel and includes a one way clutch to permit rotation of the wheel in the forward direction of the scooter without requiring commensurate rotation of the sprocket. However, rotation of the sprocket in the forward direction compels commensurate rotation of the wheel through the clutch. As is conventional, nuts  58 ,  60  threadedly engage axle  52  and secure ear  44  therebetween. Similarly, nuts  62 ,  64  threadedly engage the axle and secure ear  46  therebetween. A pair of stanchions  70 ,  72  extend upwardly from longerons  48 ,  50 , respectively, of frame  20 . The upper ends of these stanchions support a shaft  74  extending therebetween. A lever assembly  76  includes an arm  78  terminated by a sleeve  80  rotatably mounted upon shaft  74 . Thereby, level assembly  76  is rotatable about the axis of shaft  74 . The lever assembly includes a forwardly extending lever  82  supporting at it&#39;s extremity a footpad, peg or pedal  84 . The footpad, peg or pedal may be rotatably attached to the lever in the conventional manner of a foot pedal for a bicycle. The footpad, peg or pedal  84  and its attached lever  82  provide the foot drive for the gear mechanism. 
     A ratchet-like bar or rack  86  of the lever assembly extends rearwardly. It is of constant curvature and has an axis of rotation defined by shaft  74 . Bar  86  may have attached thereto a length of conventional bicycle chain or it may include a pair of sidewalls  88 ,  90  between which are mounted a plurality of rods  92  spaced apart from one another and similar to corresponding rods or pins that are the cross members of a conventional bicycle chain. The rods of bar  86  engage teeth  94  of an initial or first gear in the form of a sprocket  96 . As shown in FIGS. 1,  4  and  5 , the arm  78  and the elongate member that is the bar  86  form the arms of a single-piece yoke straddling the first gear  96 . The outer race of one or a pair of bearings  98 ,  100  are mounted upon a stud  102  secured to longeron  48  through a block  104 . The purpose of these bearings is to insure continuing engagement of bar  86  with sprocket  96 . Alternatively, a bar or strut  103  (shown in dashed lines) may interconnect end  105  of bar  86  with journaled end  107  of arm  78  (see FIG.  5 ). The variation relieves certain loads ) on bar  86  and bearings  98 ,  100  may be eliminated. Either prevents deflection of the bar  86  away from the gear  96  so as to disengage the sprocket from the rods  92 . A spring  106  (see FIG. 4) is secured intermediate the extremity of bar  86  and an anchor on frame  20  to return the bar to its forward position absent pressure on footpad  84 . Alternatively, a predetermined tension spring  108  (see FIG. 1) may be mounted on shaft  74  to return lever assembly  74  to the initial position. 
     Upon downward movement of the footpad or peg, lever assembly  76  will rotate downwardly about the axis of shaft  74  and result in curvilinear movement of bar  86 . Such movement of the bar will produce rotation of sprocket  96  due to the resulting consecutive engagement of rods  92  with teeth  94  of the sprocket. When the footpad or peg is in its lower most position, pressure is removed from the footpad or peg and the force of spring  106  (or tension spring  108 ) will draw bar  86  forwardly and rotational movement of lever assembly  76  to its initial position will occur. Commensurate rotation of first sprocket  96  in the opposite direction will also occur. 
     Referring jointly to FIGS. 2,  4 ,  5  and  7 , further details of gear mechanism  120  will be described. First sprocket  96 , mounted upon axle  52 , is in engagement with second sprocket  122  through a one way clutch  124  whereby rotation of the first sprocket in one direction corresponding with downward stroke of lever assembly  76  will result in corresponding rotation of second sprocket  122 , but rotation of the first sprocket in the other direction will have no effect upon the second sprocket. A pair of uprights  126 ,  128  extend from the rear of frame  20  and rotatably support a shaft  130 . A third sprocket  132  is fixedly attached to shaft  130 . A loop of conventional bicycle chain  134  interconnects the third sprocket with the second sprocket. A fourth sprocket  136  is fixedly attached to shaft  130 . Thus, rotation of third sprocket  132  will result in rotation of shaft  130  and fourth sprocket  136 . The fourth sprocket is attached to final sprocket  56  by a loop of conventional bicycle chain  138 . 
     The number of revolutions of first sprocket  96  is a function of the number of rods  92  present within bar  86  and therefore controls the number of revolutions of the first sprocket per downward stroke. The size of second sprocket  122  is significantly greater than the size of first sprocket  96 . The size of third sprocket  132  is significantly smaller than the size of the second sprocket and as these two sprockets are interconnected by chain  134 , the number of revolutions of the third sprocket per revolution of the second sprocket is a function of the respective ratio of teeth. Third sprocket  132  may be the same size as fourth sprocket  136 , as illustrated, or the fourth sprocket may be of greater size. Final sprocket  56  may be of smaller size than fourth sprocket  136  resulting in the final sprocket rotating more than one revolution per revolution of the fourth sprocket as a ratio of the respective number of teeth as the two are interconnected with chain  138 . Wheel  54  will rotate along with final sprocket  56  in one direction as a result of the one way clutch disposed therebetween. 
     By inspection and a basic understanding of gear mechanisms, it is evident that gear mechanism  120  will result in final sprocket  56 , and wheel  54 , rotating at a greater rate of rotation than sprocket  96 . This difference in rate of rotation is a function of the relative sprocket sizes (i.e. gear ratio) and may be changed by changing the size of one or more of the sprockets. 
     Referring jointly to FIGS. 6 a  and  6   b , details of frame  20  supporting components of gear mechanism  120  will be described in further detail. Platform  40  may include an indentation  150  for receiving the footpad, peg or pedal  84 , whereby it can become a part of platform  40  and provides an essentially planar surface upon which a rider may rest his feet. Thus, when lever assembly  76  is in its lowered position, foot pump scooter  10  may be used as a conventional scooter without interference from the lever assembly. As illustrated, a notch  152  may be incorporated to receive the corresponding part of lever  82 . A simple locking mechanism may be added (not shown) to permit the lever assembly to be latched in the depressed position. 
     The above described slots in ears  44 ,  46  are illustrated in FIG. 6 a  and identified by reference numerals  154 ,  156 . These slots permit fore and aft adjustment of axle  52  to place appropriate tension upon chains  134 ,  138  and to securely attach the axle to frame  20 . The upper ends of uprights  70 ,  72  may include an insert  160  shown in FIG. 6 b . This insert includes a slot  162  for receiving shaft  74 . Similar inserts may be mounted at the upper ends of uprights  126 ,  128  to engage and retain by nuts or the like the shaft  130 . As shaft  130  must translate rotational movement of the third sprocket to the fourth sprocket, the shaft must be journaled within the inserts at the ends of uprights  126 ,  128 , which journals are not shown as they are well known to those skilled in the art. Block  104 , for supporting bearings  98 ,  100 , extends downwardly from the bottom of longeron  48  to position the bearings adjacent the lower edge of bar  86 . 
     FIGS. 8 and 9 illustrate a lever assembly  170  that is a variant of lever assembly  76  and a variant gearing  172  of the gearing  120 . For common elements previously shown and described, the same reference numerals will be used. A pair of U-shaped support members  176 ,  176  are attached to longerons  48 ,  50 , respectively, of frame  20 . Member  174  includes an aperture  180  for receiving and engaging by axle  52  (not shown); similarly, member  176  includes an aperture  182  for supporting the axle. The ends of arms  184 ,  186  support a shaft  188 . Variant  170  of the lever assembly is pivotally mounted upon shaft  88  to permit pivotal movement of the variant in response to a downward force applied to footpad, peg or pedal  84  or in response to spring  190 . The variant includes a lever  192  for supporting footpad, peg or pedal  84 . An arced bar  194  is an elongate curvilinear member that extends rearwardly from lever  192 . An arm  196  extends from essentially the rearward extremity of bar  194  and a second arm  198  extends from essentially the junction between bar  194  and lever  192 . The two arms are joined to one another and pivotally supported by shaft  188  and in turn support the bar  194  at or near its ends. Upon downward motion of footpad  84  or peg or under the urging of spring  190  (or a tension spring  108 ), variant  170  will rock in one direction or the other about the axis of shaft  188 . Again the bar  194  and the arm  198  may be viewed as a single piece yoke and the arm  196  as a strut supporting an end of the bar  194 . 
     Bar  194  of variant level assembly  170  defines an arc about the axis of shaft  188 . The periphery of the arc portion of the bar includes a plurality of teeth  200 . These teeth engage with teeth  202  of sprocket  204 , the latter being rotatably mounted on the axle (not shown) supporting wheel  54 . As shown in FIGS. 8 and 9, the toothed bar  194  and sprocket  204  are formed here as a rack and pinion gear set. Thereby, upon depressing footpad  84  or a peg, the assembly  170  will pivot resulting in rotation of sprocket  204 . A gear  208  of greater diameter than pinion gear sprocket  204  is mechanically attached to that sprocket, whereby the gear rotates along with the sprocket. Sprocket  204  includes a one way clutch to permit rotation of the sprocket in one direction without rotation of gear  208 . Support members  174 ,  176  include uprights  210 ,  212 , respectively, for rotatably supporting a shaft  214 . A gear  216  includes teeth for meshing with the teeth of gear  208  whereby gear  208  imparts rotary motion to gear  216  resulting in rotation of shaft  214 . A sprocket  218  is fixedly attached to shaft  214  whereby the sprocket will rotate with rotation of gear  216 . A sprocket  220  is attached to wheel  54  through a one way clutch. A chain  222 , such as a conventional bicycle chain, interconnects sprocket  218  with sprocket  220 . 
     Upon depressing footpad  84 , the lever assembly  170  will pivot about shaft  188  and rotate the sprocket  204 , rotating the gear  208  to impart rotary motion to the gear  216 . The rate of rotation of gear  216  relative to gear  208  is a function of the ratio of the respective teeth. That is, due to the difference in size, gear  216  will rotate at a greater rate of rotation than gear  208 . The rotation of gear  216  rotates the sprocket  218 . Rotation is imparted to sprocket  220  through chain  222 . The rate of rotation of sprocket  220  is greater than the rate of rotation of sprocket  218  as a function of the ratio of the respective number of teeth. When footpad, peg or pedal  84  is permitted to rise in response to spring  190  (or tension spring  108 ,) sprocket  204  will rotate in the opposite direction. However, as this sprocket is secured to gear  208  through a one way clutch, rotation of this gear will not occur. Correspondingly, wheel  206  will continue to rotate as a result of forward movement of the foot pump scooter and such rotation is not impeded by the lack of rotation of sprocket  220  due to the interconnecting one way clutch. 
     A guard  230 , similar to a mud guard, serves the primary function of preventing injury to the feet of a rider by contact with either wheel  54  or any of the gears/sprockets/chains associated with variant gear mechanism  172 . 
     Referring jointly to FIGS. 10 and 11, a front drive variant  240  is illustrated. Common elements previously described have corresponding reference numerals. A pair of frame members  242 ,  244  are secured to frame  20  of the scooter  240 . A footpad, peg or pedal  246  is attached to a variant lever assembly  248 , which variant lever assembly is pivotally mounted on a shaft  250  supported by members  242 ,  244 . A curved bar  252 , similar to bar  86  shown in FIGS. 4 and 5, meshes with the teeth of a sprocket  254 . The sprocket is mounted through a one way clutch upon a shaft extending between members  242 ,  244  (the shaft is not shown for purposes of clarity of illustration). A gear  256  is in engagement with sprocket  254 , whereby the gear will rotate with rotation of the sprocket  254 . A further gear  258  is mounted upon a shaft  260  supported by frame  20  or the shaft may be supported by members  242 ,  244 . A sprocket  262  is also mounted on shaft  260  and in mechanical engagement with gear  258  to provide rotation of sprocket  262  with rotation of the ear. A chain  264 , such as a conventional bicycle chain, interconnects sprockets  262  with sprocket  266  associated with wheel  54  through a one way clutch. Thereby, rotation of sprocket  262  will rotate sprocket  266  as a function of the ratio of teeth of the respective sprockets. It may be maybe noted that gear  256  is of greater diameter than gear  258  whereby the rate of rotation of gear  258  is greater than that of gear  256  as a function of the ratio of their respective number of teeth. Thereby, gear mechanism  268  mounted at the front of the scooter  240  provides an opportunity to impart the relatively high speed of rotation to wheel  54  as a function of repetitive pumping of footpad  246 . Pivotal return of the lever assembly  248  may be effected by a spring  267  interconnecting bar  252  (or another appropriate element of the lever assembly  248 ) with frame  20  or one of members  242 ,  244 . Thereby, after the footpad  246  is depressed to urge ultimate rotation of wheel  54  and upon release of pressure on the footpad it will automatically return to its raised position. 
     Although preferred embodiments of the invention have been described in detail, it will be  22  readily appreciated by those skilled in the art that further modifications, alterations and additions to the invention embodiments disclosed may be made without departure from the spirit and scope of the invention as set forth in the appended claims.