Patent Publication Number: US-2003227154-A1

Title: Hand-pull powered scooter

Description:
FIELD OF THE INVENTION  
       [0001] This invention relates to a hand-pull powered scooter, and particularly to a novel powered scooter structure, in which the swinging movement of actuation bar is utilized to drive indirectly the horizontal rack into reciprocative movement for the driving of end gears in both strokes and both directions, so as to accelerate the rear wheels forward.  
       BACKGROUND OF THE INVENTION  
       [0002] Scooter in early stage didn&#39;t have a handbar. This causes bad balanced sense and difficulty in manipulation. Because manipulation of scooter needs long-time practicing or high balanced sense, scooter was quite limited to the use as a playing means and prevailing only for youth. Later, it has been prevailing widely to serve as a walking-substitution means after it has been developed to have a handbar and powered structure. Generally, Power source for a conventional powered scooter is either a battery for driving electric motor, or a gasoline engine, or a mechanical means etc. However, battery has heavy-weight, inconvenience in charging, and limited to working-hour problems, while gasoline engine has not only heavy-weight but also noisy, air-pollution and danger in driving problems. Therefore, these negative factors affect the consideration of using them as a means for walking-substitution.  
       [0003] In addition, a Taiwanese new utility model patent No.481160 entitled as “A powered scooter structure”, as shown in FIG. 1, discloses a structure using mechanical means for driving, comprising: a platform frame ( 10 ), a powered support bar ( 20 ), a front wheel assembly ( 30 ), a rear wheel assembly ( 40 ), a linkage mechanism ( 50 ), and a drive mechanism ( 60 ). Said front wheel assembly ( 30 )and rear wheel assembly ( 40 )are provided at the front and rear ends of the platform frame ( 10 ) respectively. One end of the powered support bar ( 20 ) is pivotally provided at the front end of the platform frame ( 10 ), and pivotally connected with one end of the linkage mechanism ( 50 ). The other end of the linkage mechanism ( 50 ) is connected with the drive mechanism ( 60 ) on the rear wheel assembly ( 40 ). Swinging movement of the powered support bar ( 20 ) actuates the drive mechanism ( 50 ) through the movement of the linkage mechanism ( 50 ), which in turn puts the rear wheel assembly ( 40 ) into rotation so as to generate the momentum for moving forward. The drive mechanism ( 60 ) includes: a transmission gear ( 63 ), a plurality of passive gears ( 64 ), engaged with the transmission gear ( 63 ) and fixed onto a fixed seat ( 61 ), and a inner gear disc ( 62 ) fixed on it. Gear portion ( 621 ) is provided on the inside peripheral wall of said inner gear disc ( 62 ) for transmission engagement with a plurality of passive gears ( 64 ). When the drive mechanism ( 60 ) is actuated by the transmission from the linkage mechanism ( 50 ), said inner gear disc ( 62 ) can move the transmission gear ( 63 ) at multiple of gear ratio, to rotate the rear wheels.  
       [0004] In ideal case, the structure of the above disclosure uses the swinging movement of the powered support bar ( 20 ) to drive uni-directionally the drive mechanism ( 60 ) on the rear wheel assembly ( 40 ). In other words, the forward stroke in the pivotal reciprocative movement of said powered support bar ( 20 ) can do work, while the return stroke just wastes power. Moreover, said rear wheel assembly ( 40 ) can only move forward at constant speed, at the fixed gear ratio of the inner gear disc ( 62 ) over the passive gears ( 64 ) and the transmission gear ( 63 ). No acceleration can be achieved.  
       SUMMARY OF THE INVENTION  
       [0005] In view of the disadvantages, especially performance, mentioned above for conventional scooter, it is the object of present invention to provide a hand-pull powered scooter, and particularly to a novel powered scooter structure, in which the swinging movement of actuation bar is utilized to drive indirectly the horizontal rack in reciprocative motion for the driving of end gears in both strokes and both directions, so as to accelerate the rear wheels forward.  
       [0006] The above and other objects can be achieved by a scooter of the present invention, comprising: a platform body which mounted on a pair of longitudinal parallel ribs, and the front end of which is connected with a headtube shaft; a frontfork, with an upper end of which is pivoted and rotates within said headtube shaft, and a lower end of which is rotatably pivoted to a front wheel; an actuation bar, an upper end of which comprises a handbar, and a lower end of which is pivotally located at the top of the headtube shaft for reciprocative swinging; a gearbox, which includes a plurality of shafts, a plurality of unidirectional gears supported on said shafts, and a plurality of reduction gears set, the front end of said gearbox being pivotally mounted on the parallel ribs, the middle end being supported below the parallel ribs via a damping spring; a guide slot provided at the top wall of said gear box; a plurality of connecting rods, the first of which is connected at the lower end of the actuation bar, and the last of which is connected to a horizontal rack; a horizontal rack, inserted into the guide slot of the gearbox, with its teeth meshed with a plurality of unidirectional gears; a pair of rear wheels rotatably supported on the central shaft of the end gear of gearbox.  
       [0007] According to the present invention, during the reciprocative movement of the horizontal rack caused by the pivoting of said actuation bar, the forward stroke of rack drives a unidirectional gear, the backward stroke another unidirectional gear, and the rack also drives the end gear in both strokes and both directions through reduction gears set, so as to accelerate the rear wheels forward continuously. In other words, the rear wheels can move at constant acceleration, when the actuation bar is continuously swinged.  
       [0008] According to the present invention, a ratchet element is pivotally provided on the end gear of the gearbox. The rear wheels rotatably supported on the shaft of the end gear can move in forward direction and stop in reverse direction. Therefore, the rear wheels will not slide downward, even if it is on a slope.  
       [0009] According to the present invention, a pair of brake pedals are provided above the rear wheels and integrally connected together by a plurality of shaft pins. One ends of this pair of brake pedals are pivotally mounted on the parallel ribs of platform body respectively, the other ends being floating, by elastic means, above the rear wheels. The rear wheels can be decelerated or stopped by the friction produced by stepping on the brake pedals. So, the manipulability of this structure is good.  
       [0010] According to this invention, a folded arm is provided between the headtube shaft and the platform body. The folded arm is fixed into position by a pair of elastic pins. Thus, the headtube shaft can be folded relative to the platform body. In addition, the actuation bar has a telescopic structure by the provision of an inner tube. Therefore, it can be folded to save space, when in unused condition. 
     
    
    
     BRIEF DESCRIPTION OF ACCOMPANIED DRAWINGS  
     [0011] Above objects, features and advantages of present invention can be further understood by the detailed description of illustrative embodiment of present invention in reference to the accompanied drawings, in which:  
     [0012]FIG. 1 is a structural schematic view of conventional “A powered scooter structure” of Taiwanese new utility model patent No.481160;  
     [0013]FIG. 2 is a perspective view of a hand-pull powered scooter of present invention;  
     [0014]FIG. 3 is a side view of a hand-pull powered scooter of present invention;  
     [0015]FIG. 4 is a plan view of a hand-pull powered scooter of present invention, wherein part of it is exploded to show the structure of a rack and gear group;  
     [0016]FIG. 5 is a cross sectional view taken along the line  5 - 5  in FIG. 4, wherein the structure of connecting rod, rack and gear group is shown;  
     [0017]FIG. 5 a  is an enlarged view of FIG. 5, in which part of members are omitted;  
     [0018]FIG. 6 is a schematic view of a hand-pull powered scooter of present invention in folded condition;  
     [0019]FIG. 7 is a schematic sectional view taken along the line  7 - 7  in FIG. 5, wherein the positioning structure of the elastic pins of the folded arm is shown; and  
     [0020]FIG. 8 is a schematic sectional view taken along the line  8 - 8  in FIG. 6, wherein the telescopic positioning structure of actuation bar is shown. 
    
    
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE PRESENT INVENTION  
     [0021] Firstly, referring to FIGS. 2, 3 and  4 , a hand-pull powered scooter  1  of the present invention includes: a platform body  10  which is mounted on a pair of longitudinal parallel ribs  11 , the, front end of which is connected with a headtube shaft  20 ; a frontfork  30  an upper end which is pivoted and rotates within said headtube shaft  20 , and a lower end which is rotatably pivoted to a front wheel  40 ; an actuation bar  50 , an upper end of which comprises a handbar  52 , and a lower end of which pivotally located at the top of the headtube shaft  20  for swinging movement; a gear box  60 , including a plurality of shafts  61   a,    61   b,    61   c,    61   d  for pivotally supporting a plurality of unidirectional gears  62   a,    62   b,  and a plurality of reduction gears set  63   a,    63   b,    63   c,    63   d  and an end gear  63 , the front end of said gearbox  60  being pivotally mounted on the parallel ribs  11 , the middle portion of said gearbox being supported below the parallel ribs  11  via a damping spring  68 ; and a guide slot  65  provided at the top wall of said gearbox  60 ; a plurality of connecting rods  71 ,  72 ,  73 ,  74 , the first connecting rod  71  being connected to a connection piece  53  at the lower end of said actuation bar  50 , while the last connecting rod  74  being connected to a horizontal rack  75  in reciprocative motion; said horizontal rack  75  being inserted within the guide slot  65  of the gearbox  60 , with its teeth meshed with a plurality of unidirectional gears  62   a,    62   b;  a pair of rear wheels  80  rotatably supported on the axle  61   d  of the end gear  64  of the gearbox  60 .  
     [0022] Again, referring to FIG. 4, 5 and  5   a,  the lower end of the actuation bar  50  of present invention is pivotally located on the top end of the headtube shaft  20  via a universal joint  54 , enabling to swinging in forward and backward direction. The swinging angle of the actuation bar  50  in forward and backward direction respectively is approximately between 5°˜25°, preferably 15° (as shown in FIG. 3), which is constrained by the gaps  541  and  541 ′, so that the swinging extent of an operator&#39;s body will not become too large. The lower end of universal joint  54  is connected with frontfork  30 , so as to rotate horizontally relative to the headtube shaft  20 . In addition, a folded arm  21  is provided between the headtube shaft  20  and the platform body  10 , for folding the headtube shaft  20  relative to the platform body  10 . A connecting piece  53  is loosely inserted at the lower end of actuation bar  50  therewith, and connecting with a horizontal rack  75  in reciprocative motion via first connecting rod  71 , second connecting rod  72 , third connecting rod  73 , and last connecting rod  74 . The teeth portion of the horizontal rack  75  is meshed with that of a unidirectional gear  62   a  on the shaft  61   a,  and another reverse unidirectional gear  62   b  on the shaft  61   b.  The middle portion of the second connecting rod  72  is pivotally located on the folded arm  21 . During the reciprocative moving of the horizontal rack  75 , via a plurality of connecting rods  71 ,  72 ,  73 ,  74 , caused by the swinging of said actuation bar  50 , the forward stroke of movement of the horizontal rack  75  drives a unidirectional gear  62   a,  while the backward stroke another unidirectional gear  62   b,  and it also drives the end gear  64  in both strokes and both directions through reduction gears  63   a,    63   b,    63   c,    63   d,  so as to move the rear wheels  80  forward continuously at constant acceleration(as shown in FIG. 5 a ). In addition, a ratchet element  66  is pivotally located on the end gear  64 . The rear wheels  80  rotatably supported on the shaft of the end gear can move in forward direction and stop in reverse direction. Therefore, the rear wheels  80  will not slide downward, even if it is on a slope.  
     [0023] According to the present invention, referring to FIG. 6, a pair of brake pedals  90  are provided above the rear wheels  80  and integrally connected together by a plurality of shaft pins  91 . Ends of this pair of brake pedals  90  are pivotally mounted on the parallel ribs  11  of platform body  10  respectively, the other ends being floating, supported by elastic means, above the rear wheels  80 . The rear wheels  80  can be decelerated or stopped by the friction produced by stepping on the brake pedal  90 . The manipulability of this structure is good.  
     [0024] According to the present invention, a folded arm  21  is provided between the headtube shaft  20  and the platform body  10 . The joint of folded arm  21  is pivotally fixed into position by a thread fastener  22 . A pair of elastic pins  23  are provided on both side of the joint of folded arm  21  respectively. Thus, the headtube shaft  20  can be folded or extended relative to the platform body  10  by these elastic pins  23 . In addition, the actuation bar  50  has a inner tube  51  inserted inside and fastened by a offset retainer  55  to form a telescopic structure (as shown in FIGS. 5 and 6). Therefore, the headtube shaft can be folded to stock or to put into a trunk of car so as to save space when in unused condition.  
     [0025] The above describes a preferred embodiment of present invention without any limitation. Variations and modifications will be readily apparent to those skilled in this art are intended to be included within the scope of this invention and subsequent claims.  
     [0026] Based on the foregoing, the reciprocative strokes of the actuation bar of the hand-pull powered scooter of this invention can drive the end gear in both strokes and both directions so as to accelerate the rear wheels forward continuously. It has good acceration performance, and can be folded to stock to save space when in unused condition. Therefore, this application is novel, inventive, and in abundance of industrial application.  
                               SYMBOL LIST OF COMPONENTS                                                1   hand-pull powered scooter           10   platform body           11   parallel rib           20   headtube shaft           21   folded arm           22   thread fastener           23   elastic pin           30   front fork           40   front wheel           50   actuation bar           51   inner tube           52   handbar           53   connecting piece           54   universal joint           55   retainer           541, 541′   gap           60   gearbox           61a, 61b, 61c, 61d   shaft           62a, 62   uni-directional gear           63a, 63b, 63c, 63   reduction gear           64   end gear           65   guide slot           66   ratchet element           68   spring           71, 72, 73, 74   connectig rod           75   horizontal rack           80   rear wheel           90   brake petal