Patent Publication Number: US-6908091-B2

Title: Cambering vehicle

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   The present continuation-in-part application relates to U.S. application Ser. No. 10/608,399, filed Jun. 23, 2003 and U.S. application Ser. No. 10/608,398, filed Jun. 23, 2003 now U.S. Pat. No. 6,880,840, the disclosures of which are hereby incorporated herein by reference. 

   BACKGROUND OF THE INVENTION 
   The present invention relates to a cambering vehicle of the type having a single front wheel extending from a vertical steering stem&#39;s lower extremity and two rear wheels, each attached to one of a pair of horizontal trailing arms pivotally attached to the steering stem. Typically, handlebars attach to the steering stem&#39;s upper extremity to permit manipulation of the single wheel. Above the rear wheels on each of the trailing arms are platforms for the user to stand on while operating the vehicle. More particularly, the cambering vehicle of the present invention also includes a novel structure which may be readily folded for storage or transport, for example. Another embodiment of the cambering vehicle of the present invention includes a novel crossbar member spanning the two trailing arms. 
   Various conventional cambering vehicles have been developed. Such conventional vehicles are generally operator propelled three wheeled vehicles comprising a front column having a steering shaft rotatably attached thereto, a front wheel attached to the bottom of the steering shaft, and a pair of laterally spaced rear wheels on trailing arms which are articulated to the front column. More complex vehicles also include additional elements, including brakes. 
   To move the vehicle, the operator stands upon platforms provided on each trailing arm. By alternately leaning left and right, the vehicle will camber left and right. This cambering induces a force between the rear wheels and a surface upon which the vehicle is placed. The force produces work driving the vehicle forward along a sinusoidal path, the frequency of which is related to the user&#39;s input of alternate leans and the amplitude of which is related to the speed of the vehicle. 
   More recent of the conventional cambering vehicles are designed to be folded into a compact configuration for storage or transport, for example. Several of the prior art cambering vehicles fold at the connection of the steering stem and the trailing arms. Other vehicles have trailing arms with intermediate folding mechanisms. Such vehicles often suffer from the application of unwanted flexing within the trailing arm. Also, such folding mechanisms typically include quick-release type features, which may cause folding of the device at inadvertent times, or which may be difficult to operate. 
   The trailing arms of conventional vehicles have their front ends rotatably or pivotally secured to the front column by utilizing an attachment fitting or shaft that is perpendicular to the front column. When the vehicle is cambered toward one side, such as the right side, the left trailing arm and thus the left rear wheel may be forced or caused to be moved upwardly away from the ground, or may not be suitably contacted with the ground. 
   Conversely, when the vehicle is cambered toward the other side, for example the left side, the right trailing arm and thus the right rear wheel may also be forced or caused to be moved upwardly away from the ground, or may not be suitably contacted with the ground, such that the vehicle may not be stable as it travels along the sinusoidal path. 
   Aspects of the present invention mitigate and/or obviate the aforementioned disadvantages of the conventional cambering vehicles. 
   SUMMARY OF THE INVENTION 
   In accordance with one embodiment of the invention, there is disclosed a cambering vehicle for human propelled transport comprising an elongate front column having a longitudinal axis; first and second pivot axles at the front column, a first trailing arm pivotally attached to the first pivot axle; a second trailing arm pivotally attached to the second pivot axle; and first and second rear wheels associated with the first and second trailing arms; wherein the first and second pivot axles are inclined from an imaginary line perpendicular to the longitudinal axis of the front column. The inclination may be downward. The front column may further comprise an internal steering stem with a front fork. The front fork may have a front wheel rotatably engaged thereto. The internal steering stem may rotate within the front column turning the front wheel to steer the cambering vehicle. The vehicle may further comprise a handle in communication with the steering stem wherein the handle is adapted so as to selectively rotate the internal steering stem within the front column. The cambering vehicle may also comprise a breaking mechanism for retarding rotation of one or both of the first and second rear wheels. Alternatively, the cambering vehicle may comprise a breaking system where the system comprises a hand actuated lever mounted upon the handle, a breaking mechanism adjacent to the first rear wheel, and a cable connecting the breaking mechanism to the hand actuated lever, where actuation of the hand actuated lever pulls the cable forcing the breaking mechanism against the first wheel with sufficient friction to retard rotation of the first rear wheel. The cambering vehicle may further comprise a cross bar linking the first trailing arm to the second trailing arm. The cross bar may comprise a first end pivotally secured to one of the first and second trailing arms with a first pin. The first pin may be selectively removably. The cambering vehicle may further comprise a cover assembly engaged with the cross bar and adapted to protect the first pin from being decoupled from the cross bar when in a first position. 
   The cover assembly may be rotatably engaged to the cross bar. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of operation, together with features, objects, and advantages thereof may best be understood by reference to the following detailed description when read with the accompanying drawings in which: 
       FIG. 1  is a perspective view of a cambering vehicle constructed in accordance with one embodiment of the present invention; 
       FIG. 2  is an exploded view of the cambering vehicle of  FIG. 1 ; 
       FIG. 3  is an enlarged partial exploded view of the cambering vehicle of  FIG. 1 ; 
       FIG. 4  is a side view of the cambering vehicle of  FIG. 1 ; 
       FIG. 5  is a top view of the cambering vehicle of  FIG. 1 ; 
       FIG. 6  is a front view of the cambering vehicle of  FIG. 1 ; 
       FIGS. 7 and 8  are enlarged partial side views illustrating the folding operation of the cambering vehicle of  FIG. 1 ; 
       FIG. 9  is a front view of a bracket which forms a part of the cambering vehicle of  FIG. 1 ; 
       FIGS. 10 and 11  are enlarged partial side views similar to  FIGS. 7 and 8  respectively, illustrating the folding operation of the cambering vehicle of  FIG. 1 ; and 
       FIG. 12  is a front view of the bracket forming a part of the cambering vehicle of the present invention, similar to  FIG. 9 , illustrating a second embodiment of the cambering vehicle; 
       FIG. 13  is an exploded view of a cambering vehicle in accordance with a third embodiment of the present invention; 
       FIG. 14  is a perspective view of the cambering vehicle of  FIG. 13 ; 
       FIG. 15  is a side view of the cambering vehicle of  FIG. 13 ; 
       FIG. 16  is a top view of the cambering vehicle of  FIG. 13 ; 
       FIG. 17  is a front view of the cambering vehicle of  FIG. 13 ; 
       FIG. 18  is a schematic view illustrating the operation of the cambering vehicle in accordance with the present invention; and 
       FIG. 19  is a partial exploded view illustrating a fourth embodiment of the cambering vehicle of the present invention. 
   

   DETAILED DESCRIPTION 
   Referring to the drawings, and initially to  FIGS. 1-6 , a cambering vehicle  1  in accordance with the first embodiment of the present invention comprises a front column  2  including a front tube  20 , a steering shaft  30 , a portion of which is rotatably engaged or disposed concentrically within the front tube  20 , a front fork  31  attached to a bottom end of the steering shaft  30  to support a front wheel  32 , and a handle  34  supported on a top end of the steering shaft  30 . 
   The steering shaft  30  may preferably be provided with a stem  33  retractably received therein and extendible outwardly therefrom, or adjustably secured to the steering shaft  30  with a device such as a quick release clamp  39 . The handle  34  is secured on top of the steering shaft  30  or on top of the stem  33  of the steering shaft  30 , if so provided. One or more, and preferably two, brake hand grips  35  are attached to the handle  34  for braking purposes, and are coupled to cables  36  respectively. 
   As shown in  FIG. 3 , the front column  2  may include an extension  21  attached to or extended from the front tube  20 , such as attached to the upper portion  22  of the front tube  20 . The extension  21  comprises an aperture  21   a  for receiving a spring-biased latch device  23 . The spring-biased latch device  23  is attached to the extension  21  of the front tube  20 , and includes a latch pin  24  extendible through the aperture  21   a  of extension  21 , downwardly toward the lower portion  25  of the front tube  20 . 
   A bracket  7  is rotatably or pivotally attached to the front tube  20  of the front column  2  with a pivot shaft  71 . For example, as shown in  FIGS. 7-8  and  10 - 11 , the bracket  7  includes a lower portion  70  rotatably or pivotally attached to the lower portion  25  of the front tube with the pivot shaft  71 , to allow the bracket  7  to be rotated relative to the front tube  20  about pivot shaft  71 . 
   The bracket  7  includes an upper panel  72  having an orifice  73  formed therein in registration with aperture  21   a  of extension  21  for receiving the latch pin  24  of the latch device  23  which may detachably or openly secure the upper panel  72  of the bracket  7  to the front tube  20 . For example, the bracket  7  may be rotated to or away from the front tube  20  when the latch pin  24  of the latch device  23  is disengaged from the upper panel  72  of the bracket  7 , as shown in  FIGS. 8 and 11 . 
   The latch device  23  comprises a circular cap  24   a  with a threaded shaft  24   b  extending therefrom. The orifice  73  of upper panel  72  may be tapped to matingly engage with the threaded shaft  24   b , such that twisting of the circular cap  24   a  in a first direction will engage the threaded shaft within the orifice. Such engagement may be utilized to lock the bracket  7 , to place the cambering vehicle  1  in the assembled condition shown in  FIGS. 7 and 10 . It will be appreciated that twisting of the circular cap  24   a  in a second direction, opposite that of the first direction, will disengage the threaded shaft  24   b  from the orifice  73  to unlock the bracket  7 , such that the cambering vehicle  1  may be placed in the folded condition shown in  FIGS. 8 and 11 . 
   Alternatively, the latch device  23  may be provided with an internal spring (not shown) mounted between the circular cap  24   a  and the threaded shaft  246 , such that the threaded shaft  24   b  is centered concentric with the spring. The spring may serve the purpose of causing the latch pin  24  to be released from the aperture  21   a  and orifice  73  upon upward force exerted on the circular cap  24   a , but be retained therein absent an external force. Preferably, the threaded shaft  24   b  will remain within the aperture  21   a  at all times during this alternate operation, even when the latch pin  24  is pulled from within the aperture  21   a  and orifice  73 . Of course, the spring rate should be sufficiently low to permit a user to easily compress the spring to withdraw the latch pin  24  from the aperture  21   a  and orifice  73 , but sufficiently high to retain the latch device  23  in a secure manner. 
   As shown in  FIGS. 7 and 10  when the latch pin  24  of the latch device  23  is engaged into the orifice  73  of the upper panel  72  of the bracket  7 , the bracket  7  may be solidly secured to the front tube  20  with the spring-biased latch device  23 . The spring-biased latch device  23  may thus be used as a latching means or device to detachably secure the bracket  7  to the front tube  20 . 
   The bracket  7  includes two socket openings  74  formed therein and defined by two frames  75  respectively. Each socket opening  74  has a longitudinal axis or pivotal axis  76  inclined relative to the longitudinal axis  77  of the bracket  7  ( FIG. 9 ) that is generally parallel to the front tube  20 , such that the socket openings  74  and/or the frames  75  may also be arranged and inclined relative to the front tube  20  when the bracket  7  is secured to the front tube  20  ( FIGS. 1 ,  4 ,  6 ,  7 ). 
   As shown in  FIG. 9 , the pivotal axes  76  of the socket openings  74  and/or the frames  75  are illustrated to be extended inclinedly and downwardly relative to the bracket  7 . However, the pivotal axes  76  of the socket openings  74  and/or the frames  75  may also be arranged in different inclination relative to the bracket  7 . For example, as shown in  FIG. 12 , the pivotal axes  76  of the socket openings  74  and/or the frames  75  may also be arranged to be extended inclinedly and upwardly relative to the bracket  7 . 
   A left trailing arm and a right trailing arm  40  each include a front portion rotatably or pivotally attached to the bracket  7  with pivot axles  78  respectively. For example, each of the trailing arms  40  includes a bushing  41  attached or provided on the front portion thereof, and rotatably attached onto the pivot axles  78  that are secured to the frames  75  of the bracket respectively, for rotatably or pivotally coupling the trailing arms  40  to the front tube  20  with the bracket  7 . 
   The front portions or the bushings  41  of the trailing arms  40  may be rotatably attached to the pivot axles  78  respectively with washers, gaskets, bearings  43  or the like, for allowing the front portions or the bushings  41  of the trailing arms  40  to be rotatably coupled to the front tube  20 . Each of the trailing arms  40  includes a downwardly dependent rear wheel  45  rotatably attached to its rear end. Each trailing arm  40  also includes a foot pedal  46  disposed thereon, to support users. 
   The front portions or the bushings  41  of the trailing arms  40  merge the pivotal axes  76  of the socket openings  74  and/or the frames  75  respectively, such that the front portions or the bushings  41  of the trailing arms  40  also arranged to be inclined relative to the longitudinal axis  77  of the bracket  7  that is parallel to the front tube  20 . 
   The cambering vehicle  1  may further include two brake devices  47  attached to the rear portions of the trailing arms  40  respectively, for braking the rear wheels  45  respectively. The brake hand grips  35  are coupled to the brake devices  47  with the cables  36  respectively, in order to actuate the brake devices  47  to brake the rear wheels  45 . Upon actuation of the brake hand grips  35 , the brake device  47  is rotated by a cable  36  such that the brake device contacts the rear wheel  45  causing friction therebetween. It will be appreciated that the components may be sized such that sufficient friction will build up to safely and quickly stop the vehicle  1  from the brake speed for which it is designed. 
   Each of the trailing arms  40  may include one or more ears  48  secured thereto or extended therefrom. The ears  48  of the trailing arms  40  typically face toward each other. A cable or a link  50  includes two ends  51  pivotally or rotatably secured to the ears  48  of the trailing arms  40  with gaskets, bearings, rubber bushings  53  or the like. One end  51  of the link  50  may be rotatably attached to the ears  48  of one of the trailing arms with a pivot pin  49 , and the other end  51  of the link  50  may be rotatably and detachably coupled to the ears  48  of the other trailing arm  40  with a fastener, a latch pin  55  or the like, for quick removal. The fastener  55  may be covered by a shield (not shown) to prevent accidental removal of the fastener. The shield may be rotatably or slidably engaged to the link  50 , such that it may easily be removed to permit a user to remove the fastener  55  from the link. A chain, string or similar device may be utilized to secure the fastener  55  to the shield, or other component of the vehicle  1 , so it will not be lost upon removal. 
   In operation, the operator alternates the shifting of his or her weight to the inside of each turning arc, to shift the center of mass to the inside of each arc. This shifting causes the front column  2  to be tilted relative to the ground, to result a series of accelerations pushing the vehicle forward in a sinusoidal path to attain a forward motion. 
   The inclination of the pivot axles  78  relative to the bracket  7  or the front tube  20  respectively may cause or generate a different moving stroke of the vehicle as compared with the moving strokes of the conventional cambering vehicles, which typically include a pair of trailing arms having front ends rotatably secured to the front column with an attachment fitting or shaft that is perpendicular to the front column. 
   The inclination of the pivot axles  78  relative to the front tube  20  of the front column  2  respectively may also be changed or selected to cause different moving stroke of the vehicle, and thus to change the accelerations of the vehicle. It is preferable, but not necessary, that the pivot axles  78  are arranged symmetric relative to the front column  2  or relative to the bracket  7 . 
   As shown in  FIG. 8 , when the latch pin  24  of the spring biased latch device  23  is disengaged from the upper panel  72  of the bracket  7 , the bracket  7  and thus the trailing arms  40  may be rotated relative to or toward the front tube  20  or the front column  2  to a compact folding or storing position. 
   As shown in  FIG. 7 , when the latch pin  24  of the spring-biased latch device  23  is engaged into the orifice  73  of the upper panel  72  of the bracket  7 , the trailing arms  40  may be solidly secured to the front tube  20  at a working position or assembled condition, and to retain the vehicle in a tricycle-shaped cambering vehicle. 
   It is to be noted that, due to the inclination of the pivot axles  78  relative to the bracket  7  or the front tube  20 , the trailing arms  40  may be rotated or spaced away from each other when the link  50  is disengaged from the trailing arms  40  to place the vehicle  1  in the folded or storing position. The foldable structure of the trailing arms  40  toward or relative to the front column  2  allows the cambering vehicle to be folded to a compact folding or storing position. 
   Accordingly, the cambering vehicle includes a left and a right trailing arm rotatably or pivotally attached to a front column with inclined axles, to allow the trailing arms and the rear wheels to be moved without being moved upwardly away from the ground, and to change the moving stroke of the vehicle. The trailing arms may also be folded relative to the front column between folding or storing positions and working positions. 
   Referring to  FIGS. 13-17 , a cambering vehicle  101  in accordance with the third embodiment of the present invention comprises a front column  102  including a front tube  120 , a steering shaft  130  rotatably engaged or disposed concentrically within the front tube  120 , a front fork  131  attached to bottom of the steering shaft  130  to support a front wheel  132 , and a handle  134  supported on top of the steering shaft  130 . 
   The steering shaft  130  may further include a stem  133  retractably received therein and extendible outwardly therefrom, or adjustably secured to the steering shaft  130  with various mechanisms, such as a quick release clamp  139 . The handle  134  is secured on top of the steering shaft  130  or on top of the stem  133  of the steering shaft  130 . One or more, for example two, brake hand grips  135  may be attached to the handle  134  for braking purposes, and are coupled to cables  136  respectively. As will be discussed, the cables  136  are routed to braking element  147 , respectively. 
   The front column  102  includes two pivot axles  121  and  122  extended from the front tube  120 , and inclined from the horizontal relative to the front tube  120 . For example, as shown in  FIG. 1 , the pivot axles  121  and  122  and illustrated to be extended inclinedly downward relative to the front tube  120 . However, alternatively, as shown in  FIG. 19 , the pivot axles  121  and  122  may also be extended inclinedly upward relative to the front tube  120 . 
   A left trailing arm and a right trailing arm  140  each include a front portion rotatably or pivotally attached to the front tube  120  of the front column  102  with the pivot axles  121  and  122  respectively. For example, each of the trailing arms  140  includes a bushing  141  attached or provided on the front portion thereof, and rotatably attached onto the pivot axles  121  and  122  respectively, for rotatably or pivotally coupling the trailing arms  140  to the front tube  120  of the front column  102 . 
   The front portions or the bushings  141  of the trailing arms  140  may be rotatably attached to the pivot axles  121  and  122  respectively with bearings  142 , washers  143 , gaskets or the like, and secured to the pivot axles  121  and  122  with fasteners  144  respectively, in order to solidly or stably couple the trailing arms  140  to the front tube  120  of the front column  102 . Each of the trailing arms  140  includes a rear wheel  145  rotatably attached to the rear end, a foot pedal  146  disposed thereon to support users. 
   The cambering vehicle  101  may further include two brake devices  147  attached to the rear portions of the trailing arms  140  respectively, for braking the rear wheels  145  respectively. The brake hand grips  135  are coupled to the brake devices  147  with the cables  136  respectively in order to actuate the brake devices  147  to brake the rear wheels  145 . 
   It is to be noted that the pivot axles  121  and  122  are illustrated or shown to be secured to or extended from the front tube  120  of the front column  102  respectively. However, the pivot axles  121  and  122  may also be provided on the front portions of the trailing arms  140 , and rotatably or pivotally attached to the front tube  120  of the front column  102  respectively with such as bushings (not shown) or the like that may be secured or extended inclinedly from the front tube  120  of the front column  102 . 
   Each of the trailing arms  140  may include one or more ears  148  secured thereto or extended therefrom, where the ears  148  of the trailing arms  140  are facing toward each other. A cable or a link  150  includes two ends  151  to be pivotally or rotatably secured to the ears  148  of the trailing arms  140  with gaskets or bearings  153  or the like. One end  151  of the link  150  may be rotatably attached to the ears  148  of one of the trailing arms  140  with a pivot pin  149 , and the other end  151  of the link  150  may be rotatably and detachably coupled to the ears  148  of the other trailing arm  140  with a fastener (not shown), a latch pin  155  or the like. 
   In operation, the cambering vehicle  101  operates in virtually the same manner as the cambering vehicle  1 , previously described. However, in order to fold the cambering vehicle  101 , one merely needs to disconnect the fastener, such as latch pin  155 , connecting the ear  148  to the trailing arm  140 . 
   Although this invention has been described with a certain degree of particularity, it is to be understood that the present disclosure has been made by way of example only and that numerous changes in the detailed construction and the combination and arrangement of parts may be resorted to without departing from the spirit of the invention as hereinafter claimed.