Patent Publication Number: US-7581611-B1

Title: Two-wheel vehicle with a tilt mechanism and stability mechanism

Description:
CROSS REFERENCE TO RELATED APPLICATION 
   The present invention is a continuation in part of U.S. application Ser. No. 11/144,997 filed on Jun. 3, 2005. 

   FIELD OF THE INVENTION 
   The present invention relates to a powered two-wheel vehicle that includes a tilt mechanism and a stability mechanism that direct the vehicle to turn while the two wheels are rotating and in contact with a surface. 
   BACKGROUND OF THE INVENTION 
   The concepts and designs of motorcycles have seen many developments since it&#39;s original inception. As electronics and mechanical developments have improved, the motorcycle continues to improve in performance. Another result of these developments is a market for smaller radio controlled versions for children and adults to utilize in a scaled down version for entertainment. When motorcycles are designed for human transportation, great care must be taken to ensure the external forces acting on the rider and vehicle are balanced. The active inputs and movements executed by a rider on a motorcycle to achieve a balanced ride carry over to the design of toy and radio controlled versions of two wheeled vehicles. These balance principles are still necessary to achieve a quality performance experience from a user, but are addressed with various mechanisms to counter external forces acting on the toy and radio controlled versions. Additionally, a segment of motor sports has gained popularity in which vehicles “drift” or “slide” through turns. This segment involves over-steering principles where a driver or rider enter turns at high speeds and then drifts through the corner while preserving a high exit speed. Principles involving the vehicle traction in combination with steering mechanics and weight elements dictate the success of drifting while moving. 
   U.S. Pat. No. 4,342,175 discloses a two-wheeled motorcycle with a frame carrying a drive motor, a servo controlled by a radio and a power source for driving the motor. The motorcycle is rear wheel driven and the front fork of the motorcycle is rotatably attached to a front wheel and a steering mechanism is attached to the top portion of the front fork which is pivotally attached to the frame of the motorcycle, such that when the center of gravity is shifted, the steering mechanism will tend to turn the front wheel in the same direction. 
   U.S. Pat. No. 4,290,228 discloses a two-wheeled toy motorcycle with side supports attached to two outriggers to bank the toy for negotiating turns. The front wheel is pivotally attached to a front fork with a steering mechanism to direct the toy&#39;s turning direction. The outriggers are cam operated from the steering mechanism and the side supports engage the surface on which the toy rests to prevent the toy from falling over sideways. However, the design is such that during operation of the toy one of the side supports will most likely be in contact with the surface, which diminishes the performance and realistic appeal of the toy. Further, the addition of a steering mechanism on the front fork creates added mechanical complexity that increases the cost of the toy while increasing the possibility of mechanical failure. 
   As one can appreciate from the examples above, prior two-wheeled toy vehicles have mechanically complicated steering configurations and have been lacking in delivering a realistic radio controlled driving experience to an adult or child. Further, the examples require a certain level of traction for the wheels and a surface in order to perform as desired. 
   One or more of the embodiments provided herein improve on past two-wheeled vehicle designs and solves the problems of stability and performance with a durable and efficient radio controlled two-wheeled vehicle with a simplistic design that takes advantage of external forces acting on a vehicle along with the physical characteristics of the two-wheeled vehicle. This quality of this vehicles performance relies on fewer variables and parts while powering both wheels and as such provides utilization on several different types of surfaces. Further, this invention provides a user with the capability to simulate a performance style known in motor sports as drifting. 
   SUMMARY OF THE INVENTION 
   In accordance with one embodiment of the present invention there is provided a two wheeled vehicle. The vehicle includes a pair of wheel housings. An annular gear rack is positioned on the inner circumference of the wheel housing and a wheel is secured on the outer circumference of the wheel housing. A chassis is connected to a frame and interconnects the pair of wheel housings to the frame such that the frame moves independently from the pair of wheel housings. A means for rotating the wheel housings by rotating the annular gear racks is also provided. A means for tilting the frame about the chassis when the wheel housings are rotating is further provided. The tilting frame causes a change in the center of gravity of the vehicle, wherein the change in the center of gravity causes forces acting on the vehicle to turn the vehicle towards changing center of gravity. In addition, a means for stabilizing the vehicle when the frame is tilting about the chassis and the vehicle is moving is also provided. The stabilizing means counteracts the forces acting on the vehicle opposite the turn and to assist in maintaining an upright position while the vehicle is turning. 
   In another embodiment the means for tilting the frame includes a tilt mechanism pivotally secured between the frame and the chassis. The tilt mechanism may also include a servo that is remotely controlled. 
   In another embodiment the means to provide vehicle stability includes a pair of protrusions defined on a base of the tilt mechanism, a pair of legs extending from a subframe member, which is pivotally attached to the tilting mechanism, each leg includes a tab defined on an upper portion thereof and a skid pad on a lower portion thereof. In addition, a pair of spring activated return mechanisms are separately positioned between the subframe member and one of the legs. In this embodiment when the tilt mechanism tilts, a protrusion opposite the tilt pushes against one of the tabs to engage and pivot one of the legs such that the skid pad is moved to a lower position, whereby the lowering of one of the legs acts to counterbalance forces exerted on the vehicle opposite the direction of the turn. 
   In another embodiment the two wheels have an outer surface with low surface friction and the low surface friction is such that the wheels are able to slip while spinning. The low surface friction causes the vehicle to turn in a drifting movement. 
   In another embodiment the means for rotating the two wheels includes at least one motor secured within one of the wheel housings. The motor drives a gear train which is meshed to the annular racks. 
   In another embodiment the vehicle is defined as having front and rear forks in both wheel housing with an axle defined in each fork. A motor drives a gear train that is meshed with outer gears that are secured onto the axle and therefore rotate the wheels when driven. 
   User inputs to a controller direct a transfer of power via a circuit board secured within the vehicle and a receiver in communication with the circuit board. The controller sends commands to the receiver, such that the circuit board can adjust a speed of the vehicle and adjust the tilting mechanism in response to the commands. 
   Numerous other advantages and features of the invention will become readily apparent from the following detailed description of the invention and the embodiments thereof, from the claims, and from the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A fuller understanding of the foregoing may be had by reference to the accompanying drawings, wherein: 
       FIG. 1   a  is a perspective view of a first embodiment of a two-wheel vehicle in accordance with the present invention; 
       FIG. 1   b  is a front view of  FIG. 1   a;    
       FIG. 2   a  is a perspective view of a tilt mechanism and stability mechanism included in a first and second embodiment of a two-wheel vehicle in accordance with the present invention; 
       FIG. 2   b  is a front view of  FIG. 2   a;    
       FIG. 2   c  is a perspective view of a tilt mechanism and stability mechanism illustrating the tilt mechanism engaging the stability mechanism when the tilt mechanism pivots during a turn; 
       FIG. 2   d  is a front view of  FIG. 2   c;    
       FIG. 3   a  is a perspective view of a first embodiment of a two-wheel vehicle in accordance with the present invention illustrating the frame of the vehicle is tilted to one side; 
       FIG. 3   b  is a front view of  FIG. 3   a  illustrating a tilt mechanism engaging a stability mechanism where a tilt mechanism tilts the frame to one side; 
       FIG. 4  is a perspective view of a first embodiment of a two-wheel vehicle in accordance with the present invention where the housings are removed, illustrating the drive motor and transfer gear train relationship; 
       FIG. 5  is a perspective view of a second embodiment of a two-wheel vehicle in accordance with the present invention; and 
       FIG. 6  is a perspective view of a second embodiment of a two-wheel vehicle in accordance with the present invention where a housing is removed, illustrating the drive motor and transfer gear train relationship. 
   

   DETAILED DESCRIPTION OF THE EMBODIMENTS 
   While the invention is susceptible to embodiments in many different forms, there are shown in the drawings and will be described herein, in detail, the preferred embodiments of the present invention. It should be understood, however, that the present disclosure is to be considered an exemplification of the principles of the invention and is not intended to limit the spirit or scope of the invention and/or claims to the embodiments illustrated. 
   Referring now to  FIGS. 1   a  and  1   b , there is shown a two-wheeled vehicle  10 . The vehicle  10  includes a front wheel  15  and a rear wheel  20  secured to a rotatable front wheel housing  25  and a rear wheel housing  30 , respectively, such that when the front and rear wheels housings rotate, the front and rear wheels rotate therewith. Both the front wheel housing  25  and the rear wheel housing  30  are separately secured to a chassis  35  through a gear train  45 , which is further operably connected to a motor (discussed in greater detail below) for driving and thus rotating the front and rear wheels. The chassis  35  is connected to a frame  50  and interconnects the wheel housings to the frame such that the frame moves independently from the wheel housings. Also included are a first means  55  for tilting the frame  50  and a second means  57  for stabilizing the frame  50  while tilting. 
   Referring now also to  FIGS. 2   a  through  2   d  the first means  55  for tilting the frame  50  and the second means  57  for stabilizing the frame  50  are mechanically illustrated. The first means  55  for tilting the frame includes a tilt mechanism  59  pivotally connected at an axis  60  to a subframe member  64 . The subframe member  64  is secured to the chassis  35 . Therefore, the frame  50  is secured to the tilt mechanism  55 , which is further pivotally secured to the chassis  35 . 
   The tilt mechanism  59  also includes a servo remotely controlled by a hand-held remote control unit (not shown). The servo is operably connected to the frame  50  and pivots about the axis  60 . A servo motor pivots the tilt mechanism  55  when controlled by the remote controller unit (not shown). The tilt mechanism  55  includes a servo housing secured to the frame  50 . The servo motor is pivotally connected to a servo axle on axis  60  that is secured to the chassis  35 . The servo motor within the servo housing drives a servo gear train causing the tilt mechanism  55  to pivot on the servo axle and thus causing the tilt mechanism  55  to lean to one side or the other. A character or figure may optionally be secured to the frame  50 . The tilt mechanism  55  may also include a variable resistor that determines when the tilt mechanism  55  is centered and determines the degree of tilt. The degree of tilt dictates the sharpness or softness of the turns. Other well known means to locate a center position and other tilt positions may be used. 
   The second means  57  for stabilizing the frame  50  while the vehicle  10  is turning, is defined by providing a stability mechanism. The stability mechanism includes a pair of protrusions  65  extending from opposite ends of the base  62  defined by the tilt mechanism  59 . The stability mechanism further includes a pair of legs  70  pivotally secured a spring activated return mechanism  95 . The spring activated return mechanism  95  is attached to the subframe member  64 . Each of the two legs  70  includes a tab  75  and a skid pad  85 . 
   To turn the vehicle  10 , a user remotely pivots the tilt mechanism  55  about the pivot axis  60 . The center of gravity of the vehicle  10  will shift with the pivoting of the tilt mechanism  55 . The shifting of the center of gravity towards one side will add a torque to the angular momentum defined in the moving vehicle  10 , causing the vehicle to lean towards (or turn) into the side of the center of gravity shift. This is done in order to maintain and conserve the angular momentum of the vehicle  10 . When the tilt mechanism  55  pivots, the protrusion  65  on the opposite side of the lean contacts and pushes the corresponding tab  75 . The corresponding tab  75  when pushed pivots its attached leg  70  about a pivot point  97  moving the skid pad  85  downwardly (further illustrated in  FIGS. 3   a  and  3   b ). The lowered positioning of the leg  70  assists in counterbalancing forces exerted on the vehicle  10  that would normally pull the vehicle in a direction opposite to the desired turning direction. As such, the tilt mechanism  55  and the stability mechanism  57  counterbalance the forces exerted on the vehicle  10  to provide a user to direct the vehicle  10  to perform a number of driving maneuvers and tricks. One such performance example deals with a steering and performance style known as “drifting.” Drifting refers to a driving and/or riding technique to proceed through a turn with a vehicle such as a car or motorcycle. Over-steering principles are used such that a driver or rider enter a turn at a high speed and then drift through the corner while preserving a high exit speed. In this invention, the two-wheel vehicle  10  drifts by intentionally losing lateral wheel grip while using steering (in this case, utilizing the tilt mechanism  55  to shift the weight of the vehicle  10 ) and throttle inputs to direct the vehicle  10  through a turn. In addition, the front wheel  15  and rear wheel  20  may be made of materials with a low surface friction to help enable a drifting effect through a turn while maintaining speed. 
   The speed or rate of rotation of the front wheel  15  and the rear wheel  20  are controlled with the remote control unit (not shown). The remote control unit also controls the degree of pivoting of the tilt mechanism  55 . It should be appreciated that the higher degree of pivoting the sharper the turn. The remote control unit may use infra red, radio waves, optical sensors or other well-known communication means. The front wheel  15  and the rear wheel  20  may both have a flat surface on the outer circumference to enable the vehicle to stand in a vertical position (when not moving) without support from an outside source. Both wheels are secured to their respective rotatable wheel housings, such that both wheels are able to spin while the chassis  35  remains in a constant position if so desired. 
   Now referring to  FIGS. 1   a  and  4 , the means to rotate the wheels includes a drive motor  145  secured within the front wheel housing  25 . The drive motor drives a gear train  45  that is meshed to a pair of gear racks  135 , separately positioned on the inner circumference of the wheel housings. The drive motor  145  sits in a motor housing defined by two side plates  155  included in the front wheel housing  25 . The drive motor or a second drive motor may also be positioned in the rear wheel housing if desired. When the drive motor  145  is operating, the gear train  45  distributes an equal amount of power to drive the front wheel  15  and the rear wheel  20 , and may be driven in either a forward or reverse direction. Balance of the rotating wheels is further accomplished by providing multiple points of contact with the wheel housing defined as guides  99 . Each guide  99  has three points of contact with its respective wheel housing. However, more or less contact points may be utilized without deviating from the scope of the invention; in fact it is further contemplated that the present embodiments may not include guides at all. On the front wheel  15 , two of the points of contact are positioned on the inner circumference of the front wheel housing  25  at a pair of front inner positioning wheels  100  and the third point of contact is a front outer positioning wheel  105  located on the outer circumference of the front wheel  15 . On the rear wheel  20 , two of the points of contact are positioned on the inner circumference of the rear wheel housing  30  at a pair of rear inner positioning wheels  110  and the third point of contact is a rear outer positioning wheel  115  located on the outer circumference of the rear wheel housing  30 . Both pairs of positioning wheels  105  and  110  spin on axles  120  secured to the corresponding housing, while the outer positioning wheels spin on axles external to the wheels and secured to the chassis  35 . Both sets of the inner positioning wheels include two cylindrical discs  130  having a space therebetween to receive gear racks  135 . 
   During operation, the front wheel  15  and rear wheel  20  rotate making contact with a surface to propel the vehicle  10 . As the speed of the rotating wheels increases, gyroscopic forces and the angular momentum of the wheels keep the vehicle  10  upright. In addition, when the speed decreases, inertia of the rotating wheels also keep the vehicle upright. 
   In a second embodiment as illustrated in  FIGS. 5 and 6 , there is a two-wheeled vehicle  200 . The vehicle  200  includes a chassis with a front fork  225  and a rear fork  230 , a front wheel  205  and a rear wheel  210  rotatably secured to a front axle  215  and a rear axle  220 , respectively. The front axle  215  is secured to the front fork  225  and the rear axle  220  is secured to the rear fork  230 . Further, a means for rotating the front wheel  205  and the rear wheel  210  is secured to the chassis. The chassis is connected to a frame  240  and interconnects the wheel housings to the frame such that the frame moves independently from the wheel housings. 
   During operation, the front wheel  205  and rear wheel  210  rotate making contact with a surface to propel the vehicle  200 . As the speed of the rotating wheels increases, gyroscopic forces and the angular momentum of the wheels keep the vehicle  200  upright. In addition, when the speed decreases, inertia of the rotating wheels also keep the vehicle  200  upright. The tilting and stabilizing means described above are utilized in the same manner for the second embodiment and thus further comment is not provided. 
   Continuing to referring to  FIGS. 5 and 6 , a means for rotating the front wheel  205  and the rear wheel  210  includes a drive motor  290  that drives a gear train  295 . The drive motor  290  has a drive gear  300  and is secured within a motor housing. The drive gear  300  is meshed with the gear train  295  to transfer power. The gear train  295  is meshed with a front axle gear  310  and a rear axle gear  315 . The front axle gear  310  is rotatably secured to the front axle  215  and the rear axle gear  315  is rotatably secured to the rear axle  220 , such that power is transferred from the transfer gear train  295  to both the front axle  215  and rear axle  220  to drive the front wheel  205  and rear wheel  210  in either a forward or reverse direction. 
   It is also important to note that the embodiments disclosed herein cover a radio controlled two-wheeled vehicle, that utilizes the combination of two wheels and a tilt mechanism for movement where the wheels are powered for forward and rearward movement and where the tilt mechanism adjusts the center of gravity of the vehicle to turn in the left and right directions. In addition, the vehicle&#39;s movement is radio controlled by a user. It should be further noted that while the embodiments disclose a flat surface and a rounded surface for the wheel, the present invention may also utilize other surfaces with different textures and shapes. 
   From the foregoing and as mentioned above, it will be observed that numerous variations and modifications may be effected without departing from the spirit and scope of the novel concept of the invention. It is to be understood that no limitation with respect to the specific methods and apparatus illustrated herein is intended or inferred. It is intended to cover by the appended claims all such modifications as fall within the scope of the claims.