Abstract:
A self propelled scooter that has a pair of wheels that ride on the ground and a frame having a footboard mounted between the wheels. The rear wheel has a shiftable axle, that is, the axle that rotatably affixes the rear wheel to the frame can be moved between a location that is at the center of the rear wheel where the user can readily coast the scooter and a location offset with respect to the center of the wheel where that offset location allows the user to employ a pumping action and use the weight of the user on the footboard to propel the scooter forwardly. A mechanism operable by the user allows the user to selectively move the rear axle between the two locations so that the user can pump the scooter to gain speed when the axle is in the offset location and then shift the axle back to the center location to dissipate that speed by allowing the scooter to coast.

Description:
RELATED APPLICATIONS 
     The present application is based upon U.S. Provisional Patent Application Serial No. 60/278,210 filed Mar. 23, 2001 and entitled SCOOTER WITH PUMPING MECHANISM. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to a scooter, and more particularly, to a self propelled scooter that can be propelled by the weight of the user applied at periodic time intervals to the scooter. 
     There are, of course, a considerable number of different scooters that are in use and which have been proposed for adults or children to use as pleasure vehicles and recreation. Of course the classic scooter is simply comprised of a frame that extends between two wheels and those wheels are rotatably affixed to the frame by means of axles that are affixed to the frame at fixed spaced apart locations and such axles are positioned at the center of the circular wheels. Accordingly, the user can maintain one foot on a footboard area of the frame intermediate the wheels and use the other foot to make intermittent contact with the ground to push the scooter forwardly. 
     Aside from the traditional scooter, however, there are also other scooters that can be self-propelled in the sense that there is some mechanism built into the scooter that can be activated by the foot of the user to employ the weight of the user to produce a force to propel the scooter forwardly. An example of such a scooter is shown and described in U.S. Pat. No. 3,086,795 of Hatcher et al where the footboard of the scooter is affixed to the rear wheel at an axle position that is offset from the center of the rear wheel so that the user can shift his weight up and down in a pumping action to propel the scooter over the ground. By such motion, therefore, the scooter can be, in a manner, self-propelled by the user without the normal intermittent contact with ground. A difficulty with the Hatcher et al scooter, however, is that the user cannot easily coast since the eccentric position of the rear axle will continue the up and down motion as long as the scooter is moving over the ground and is not efficient for coasting. 
     A further example of a self-propelled scooter is shown and described in U.S. Pat. No. 5,224,724 of Greenwood where an additional axle is provided that is separately propelled by a rocking lever that cooperates with the offset mechanism in the rear wheel to move the scooter forwardly without need of the user having to make the intermittent contact with the ground. Again, however, there would seem to be no way to coast with the Greenwood scooter since the lever action would continue to move up and down as the user moves the scooter. 
     Accordingly, it would be advantageous to have a scooter that would be relatively easy to manufacture and assemble and which is propelled by the user by some offset axle mechanism that utilizes the weight of the user to bring about the forward motion of the scooter while, at the same time, also have the ability of the user to simply coast so that the user can take advantage of the speed achieved to rest or in riding the scooter down a hill and the up and down pumping is not needed to move the scooter forwardly. 
     SUMMARY OF THE INVENTION 
     Therefore, in accordance with the present invention, there is provided a specially constructed scooter that combines the features of a self propelled scooter with the ability to simply coast on the scooter and not continue the pumping action. 
     Accordingly, with the present scooter, there are a pair of circular wheels that ride on the ground as the scooter is propelled. There is a scooter frame that extends between the wheels and each wheel has an axle with which the wheels are affixed to the frame so that the wheels are rotatably affixed to that frame. A footboard is provided on the frame intermediate the wheels for the rider to place one or both feet in riding the scooter. 
     One of the wheels, preferable the rear wheel, has a mechanism that allows the user to selectively move the axle from the center of the rear wheel to an offset or eccentric position that is radially displaced with respect to the center of the wheel. As such, the user can selectively move the axle to which the frame is connected between two positions i.e. a first position located at the center of the wheel so that the user can easily and efficiently coast on the scooter and a second position that is offset or eccentric with respect to the center of the wheel so that the user can employ the pumping action and use the weight of the user to propel the scooter forwardly. In addition, the scooter of the present invention is useful as an exercise device as the pumping motion technique is conducive to providing exercise to the user in a fun environment. 
     Other features of the self-propelled, multi-axle scooter will become apparent in light of the following detailed description of a preferred embodiment thereof and as illustrated in the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 illustrates prior art, and is a schematic view of a conventional scooter that can be coasted in normal manner; 
     FIG. 2 illustrates prior art, and is a schematic view of a scooter having an offset axle that can be self propelled by a pumping motion by the user; 
     FIG. 3 illustrates prior art, and is a further schematic view of the scooter of FIG. 2; 
     FIG. 4 is a side view of a scooter wheel constructed in accordance with the present invention; and 
     FIG. 5 is a side view of a mechanism to change the axle position of a scooter in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to FIG. 1, there is shown a schematic view of a conventional scooter and which comprises a front wheel  10 , a rear wheel  12  and a scooter frame  14  that spans between the front and rear wheels  10 ,  12  and includes a flattened area or footboard  16  where the user can position one or both feet as the scooter travels over the ground. At the front of the scooter is a set of handlebars  18  to be gripped by the hands of the user in using the scooter in conventional manner. 
     As also is conventional, both of the front and rear wheels  10 ,  12 , has an axle  20  that allows the front and rear wheels  10 ,  12  to rotate freely while remaining affixed to and be supportive of the scooter frame  14  and to position that scooter frame  14  above the ground. As is normal, with the use of the scooter shown, the rider may maintain one foot on the footboard  16  while the other foot makes an intermittent pushing contact with the ground to propel the scooter forwardly and when a sufficient speed is attained, the user can easily coast by keeping the propelling foot off the ground or by positioning both feet riding on the footboard  16 . 
     The coasting action is achieved in that the axle  20  of the scooter is positioned at the center of both the front and rear wheels  10 ,  12 , that is, the axles  20  of the wheels are in the geometric center of the circular wheels. That center of the rear wheel  12  is designated as C in the Figure and the forward direction of the rear wheel  12  is designated by the arrow A. 
     Turning next to FIGS. 2 and 3, there is shown a further scooter, again, using the same convention as in FIG. 1, there is a front wheel  10 , a rear wheel  12  and a scooter frame  14  extending therebetween and affixed to axles  20  on the front and rear wheels  10 ,  12 . In the FIGS. 2 and 3 embodiment, however, the rear axle  20  is located at a position designated B which, as can be seen, is offset, or radially displaced with respect to the center C of the rear wheel  12 . 
     Thus in the FIGS. 2 and 3 embodiment, the scooter can be self propelled without need for the intermittent pushing contact with the ground, that is, the scooter can be powered over the ground by means of a pumping action by the user employing the users weight at certain intervals acting on the footboard  16 . To further explain, in FIG. 2, the offset axle B can seen to be approaching its downward motion of the scooter moving forwardly and with the rear wheel  12  moving in the direction of the arrow A and at this point, the user can push downwardly using the weight of the user on the footboard  16  while at the same time pulling rearwardly on the handlebars  18 , shown by the arrow D and force the scooter in the forward direction. 
     Conversely, in FIG. 3, the offset axle B is starting its upward movement and the user can lift upwardly with the users weight and push forwardly on the handlebars  18  in the direction of the arrow E to encourage the offset axle B to again reach the uppermost point in its travel to again deliver a power stroke. 
     In the aforedescribed manner, the scooter of the embodiment shown in FIGS. 2 and 3 can be self-propelled without the user contacting the ground. A difficulty arises, however, in that the user cannot readily coast with that embodiment as the offset axle  20  at the position B prevents a smooth coasting action. Therefore, in the event the user is traveling downhill or has attained sufficient speed that a rest is desired, it is simply not possible to coast the scooter smoothly. 
     Accordingly, turning now to FIGS. 4 and 5, there is shown, respectively, a side view of a bi-axle position wheel  22  suitable for use on a scooter in carrying out the present invention and a side view of a shifting mechanism that is used with the present invention to carry out the shifting of an axle position for a vehicle such as a scooter. As will be seen, the present invention can be used for a variety of differing vehicles, however for purposes of the present specification, the invention will be described with specific reference to a scooter. The present invention has the self-pumping feature of the embodiment of FIGS. 2 and 3 and yet attains the smooth coasting of the embodiment of FIG. 1 by providing a shifting mechanism that allows the user, at will, to shift the location of the axle of the rear wheel between a center position of the FIG. 1 embodiment and the offset position or eccentric axle of the embodiment of FIGS. 2 and 3. 
     Basically, the present invention comprises two devices. First, there is a wheel that is bi-stable and has two axle positions, one of which is in the center of the wheel and therefore appropriate for coasting of the scooter and the other axle position is offset or eccentric from the center of the wheel and therefore is applicable to use of the pumping motion to self propel the scooter. Secondly, the other basic device is a mechanism, activatable by a user, to enable that user to shift the axle position between those two axle positions to take advantage of the features of both axle positions. 
     Taking, therefore FIGS. 4 and 5, in FIG. 4 the wheel  22  having two axle positions is shown and in FIG. 5, the mechanism for shifting the axle between those two positions is shown. 
     Thus, taking first FIG. 4, the wheel  22  is shown and which travels over the ground by rotating in the direction of the arrow F. The wheel  22  itself is preferably an aluminum wheel, which may be constructed of two circular aluminum plates fastened together, or a single piece of aluminum or other metal can be used, and which also has a rubber tire (not shown) affixed to the outer peripheral surface of the wheel  22 . As can be seen the scooter frame  24  terminates in a pair of bifurcated forks  26 , spaced apart, and the scooter axle  28  fits intermediate each of the forks  26  much the same as in a conventional bicycle and it should be noted that the axle  28  remains affixed within the pair of forks  26  throughout the further shifting procedures of this invention. 
     The fork  26  is shown in the solid position in FIG. 4 when the axle  28  of the scooter is located in the center of the wheel  22  and in the dotted line position when the axle  28  is in its offset or eccentric position with respect to the center position. Thus, the axle  28  can be shifted between the center position, position X and the eccentric position, shown as position Y. That shifting can be accomplished by means of a axle lever  30  that is pivotally mounted to the wheel  22  at the axle lever pivot point  32  and can pivot between the solid line position where the axle  28  is in position X and the dotted line position where the axle  28  is in position Y. A pair of stops  34 ,  36 , also affixed to the wheel  22 , limit the angular movement of the axle lever  30  to the solid line and dotted line positions. The axle lever  30  is also affixed to the axle  28  and to a roller  38 . Thus, as the axle lever  30  moves so do the axle  28  and the roller  38 . 
     A latch lever  40  is also pivotally affixed to the wheel  22  at a latch lever pivot point  42  and is biased to the solid line position shown in FIG. 4 by means of a spring  44 . A stop  46  holds the latch lever  40  in the solid line position and biased to that position by the spring  44 . A first cam  48  is affixed to the latch lever  40  and a second cam  50  is also affixed to the latch lever  40 , the purpose of the first and second cams  48 ,  50  will be later explained. There are also a pair of partial circular recesses, shown as a first circular recess  52  and a second circular recess  54  formed in the latch lever  40 . 
     As can now be seen, the roller  38  fits within the first circular recess  52  when the axle  28  is located in the solid line position or position X, that is, where the axle  28  is located at the center of the wheel  22  and therefore the scooter can coast freely. When, on the other hand, the roller  38  is located in the dotted line position, or within the second circular recess  54 , the axle is in its position Y, and is eccentric to the center of the wheel  22  so that the scooter can be pumped to provide the forward motive power. 
     Thus, by simply shifting the axle  28  where the roller  38  is captured within the first or second circular recesses  52 ,  54 , the axle lever  30  can be locked into position X or position Y. To move that roller  38  between those two positions, the axle lever  40  can move by gravity when it is released from the constrained positions where the roller  38  is captured within the first or the second circular recesses  52  and  54 . As also can be seen, the latch lever  40  can be moved from its solid line position where the roller  38  is captured within one of the circular recesses  52 ,  54 , to the dotted line position where the latch lever  40  releases the roller  38  to be free to move between the X and Y positions where the roller  28  is, respectively, captured in one of the circular recesses  52 ,  54 . 
     To release the roller  38 , therefore, the latch lever  40  only needs to be moved from its solid line position biased by the spring  44  to the dotted line position and, as can be seen, that movement can be effected by moving either the first cam  48  in the direction of the arrow G or by moving the second cam  50  in the direction of the arrow H, that is, if either the first or second cams  48 ,  50  are moved, both cams will effectively move. 
     Accordingly, the means to move the first and second cams  48 ,  50  is provided by the mechanism that is shown in FIG.  5  and will be explained also with reference to FIG.  4 . Thus, turning to FIG. 5, there is shown a side view of the mechanism that is used to move the first and second cams  48 ,  50  to move the latch lever  40  to its dotted line position to allow the roller  38  to move between position X and position Y. In this Figure, the fork  26  is shown and there is a mounting block  56  that is affixed to the axle  28  at fork  26  and that mounting block  56  is affixed external to the twin forks  26 . As shown in the Figure, the mounting block  56  is positioned on the far side of the wheel  22  of FIG.  4 . 
     Pivotally affixed to the mounting block  56  is a pair of levers, identified as a first lever  58  and a second lever  60 . The first lever  58  is pivotally affixed to the mounting block  56  at a first lever pivot point  62  and the second lever is pivotally affixed to the mounting block  56  at a second lever pivot point  64 . Each of the first and second levers  58 ,  60  has a actuator cam, identified as a third cam  66  and fourth cam  68 . The third and fourth cams  66  and  68  are movable along with the first and second levers  58 ,  60  to contact and move the first and second cams  48 ,  50  of FIG. 4 to move the latch lever  40  in releasing the axle  28  for movement between position X and position Y. 
     To therefore move the first and second levers  58 ,  60  a Bowden cable  70  is provided that is routed to a lever located on the handlebars, much the same as with a hand brake activator or hand grip  72  found on many bicycles. As such, the other end of the Bowden cable  70  has its outer sheath  74  affixed to the mounting block  56  by a clamp  76  and the inner wire  78  extends outwardly and is connected to the second lever  60  at a post  78 . Thus, when the inner wire  78  is pulled into the Bowden cable  70  as the user squeezes the hand grip  72  at the other end of the Bowden cable  70 , the second lever  60  moves in the direction of the arrow J and moves the fourth cam  68  into direct contact with the second cam  50  as the rotating wheel  22  passes by such that the latch lever  40  disengages from the roller  38  and the axle  28  is free to move to the concentric position, or position X by the force of gravity. When in the concentric or position X, the scooter is free to coast without hindrance to the user. 
     The same means is used to move the roller  38  back to the position Y since, by activating the inner wire  78 , the movement of the second lever  60  also rotates the first lever  58  by means of a connecting link  82  and which therefore rotates the first lever  58  about its first lever pivot point  62  in the direction of the arrow K. That movement shifts the third cam  66  toward the first cam  48  and therefore that third cam  66  contacts the first cam  48  to move it in the direction of the arrow G on FIG. 4 to cause the latch lever  40  to move out of engagement with roller  38  and, again, by gravity, the axle  28  moves from the concentric position X back to the eccentric position Y such that the scooter is in the pump mode and the user can motivate the scooter by the pumping action. 
     Accordingly, the present mechanism and the specially constructed wheel  22  and the use of a hand grip  72  positioned on the handlebars, allow the location of the axle  28  to move between the centered position X where the scooter can coast and the eccentric position Y where the user can pump the scooter to propel the scooter over the ground. 
     It will be understood that the scope of the invention is not limited to the particular embodiment disclosed herein, by way of example, but only by the scope of the appended claims.