Patent Publication Number: US-2006009119-A1

Title: Toy vehicle with stabilized front wheel

Description:
REFERENCE TO RELATED APPLICATION  
      This application claims the benefit of and priority to prior filed co-pending U.S. Provisional Patent Application Ser. No. 60/586,561 to Hoeting et al., filed Jul. 9, 2004, entitled “Toy Vehicle with Stabilized Front Wheel,” having Attorney Docket No. BGZ-32, which is hereby incorporated by reference herein in its entirety. 
    
    
     FIELD OF THE INVENTION  
      The present invention relates generally to a toy vehicle, and more particularly, to a toy vehicle with a stabilized front wheel.  
     BACKGROUND OF THE INVENTION  
      Toy vehicles, and in particular toy motorcycles are generally known in the art. Toy motorcycles typically include a chassis supported along a longitudinal axis by front and rear wheels. Because a toy motorcycle must balance upon those two wheels, wind and other external forces can easily cause the toy motorcycle to fall over. For example, when a toy motorcycle is in motion, bumps in the terrain can cause the motorcycle to become off balance. Without the use of any stabilization system, toy motorcycles, and especially remotely controlled toy motorcycles, are difficult to operate and likely to fall over.  
      Several approaches have been tried to enhance a toy motorcycle&#39;s stability. For example, the stability of the motorcycle can be enhanced by utilizing a four-bar linkage steering mechanism as described and claimed in U.S. Pat. No. 6,095,891 (“the &#39;891 patent”), issued to Hoeting et. al. and entitled “Remote Control Toy with Improved Stability.” The four-bar linkage projects a castering axis ahead of the front wheel to help stabilize the toy motorcycle, especially over rough terrain.  
      Gyroscopic flywheels can also enhance the stability of the toy wheels. For example, the &#39;891 patent discloses a weighted flywheel assembly housed within and operatively associated with the rear wheel of the toy vehicle. A propulsion drive is operatively coupled to both the rear wheel and the flywheel assembly, and drivingly rotates both the rear wheel and the flywheel assembly. During operation, the flywheel assembly rotates substantially faster than the rear wheel thereby causing a gyroscopic effect that tends to prevent the toy vehicle from falling over.  
      While the stabilization approaches discussed above improve the stability of toy motorcycles, Applicants believe that stabilization can be achieved via other approaches as well.  
     SUMMARY OF THE INVENTION  
      The present invention provides a toy vehicle with a flywheel operatively associated with a front wheel. The toy vehicle comprises a chassis having a front end supported by the front wheel and a rear end supported by a rear wheel. A motor is operatively connected to the flywheel to rotate the flywheel and generate a gyroscopic effect while the toy vehicle is moving.  
      The flywheel of the present invention is adapted to rotate independently of the front wheel. For example, the front wheel may be adapted to freely rotate about an axle that is fixedly attached to the front end of the chassis. The motor may be positioned in a motor mount that is fixedly connected to the axle such that the motor does not rotate about the axle. Accordingly, the front wheel rotates about the axle whenever the toy vehicle is in motion whereas the flywheel rotates about the axle whenever the motor is energized. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with a general description of the invention given above, and the detailed description given below, serve to explain the invention.  
       FIG. 1  is a side view, partially cut away, of a toy motorcycle in accordance with the present invention;  
       FIG. 2  is a side view similar to  FIG. 1  showing internal components of the toy motorcycle;  
       FIG. 3  is a top view of the toy motorcycle in  FIG. 1  showing the operation of the steering servo;  
       FIGS. 4A and 4B  are exploded perspective views of the front wheel of the toy motorcycle shown in  FIG. 1 ;  
       FIG. 5  is an exploded perspective view similar to  FIG. 4A  showing an alternate flywheel design;  
       FIG. 6  is a cross-section view of the front wheel of the toy motorcycle shown in  FIG. 1 ; and  
       FIG. 7  is a cross-section view similar to  FIG. 6  showing an alternate front fork design. 
    
    
     DETAILED DESCRIPTION  
      With reference to  FIGS. 1 and 2 , a toy vehicle  10  is shown according to the present invention. As illustrated and described herein, the toy vehicle  10  is a toy motorcycle, and in particular, a remote-controlled toy motorcycle. The toy vehicle  10  includes a chassis  12  that has front and rear ends  14 ,  16 , a front fork  18  operatively connected to the front end  14 , and a rear suspension  20  operatively connected to the rear end  16 . The front fork  18  is supported by a front wheel  24  that is adapted to steer the toy vehicle  10  in a desired direction. The rear suspension  20  is supported by a rear wheel  26 . A flywheel assembly  28  is operatively associated with the front wheel  24  to stabilize the toy vehicle  10  when the toy vehicle is moving. The flywheel assembly  28  will be explained in greater detail below.  
      As shown in  FIG. 1 , the chassis  12  includes a decorative shell or casing  30  that covers the internal components of the toy vehicle  10  and defines the general shape of the chassis  12 . The components of an actual motorcycle may be depicted graphically on the shell  30  to increase the aesthetic value and consumer appeal of the toy motorcycle  10 . For example, an engine  34 , transmission assembly  36 , drive chain  38 , and body frame  40  are all depicted graphically on shell  30  in  FIG. 1 , even though none of those features are functional. The toy vehicle  10  may also include a simulated rider (not shown) sitting upon the chassis  12  and gripping handlebars  42  which are attached to the front end  14 .  
      To increase the operability of the toy vehicle  10 , body extensions  48 , such as foot pads, may extend outwardly from shell  30 . The body extensions  48  are adapted to provide support for the chassis  12  when the toy vehicle  10  is on its side such that the rear wheel  26  remains in contact with the ground. Accordingly, the toy vehicle  10  can, in most situations, right itself when it is lying on its side without intervention from the operator. That is, upon application of drive power to the rear wheel  26 , the toy vehicle  10  begins to spin in an arcuate path until the vehicle becomes upright and is able to operate on both its front and rear wheels  24 ,  26 . This self-righting characteristic is attractive to the operator of the toy vehicle  10  because the operator does not have to walk over to where the toy vehicle  10  is on its side. Normally, the application of power to the rear wheel  26  is all that is required to get the toy vehicle  10  back into operation.  
      As shown in  FIG. 2 , the chassis  12  supports numerous internal components, such as a propulsion drive  54  and a steering drive  56 , that are enclosed or covered by the shell  30 . More specifically, the chassis  12  supports a power supply  58 , a rear drive motor  60 , and a steering servo  62 , which are all electrically coupled to a control board  64  that is supported on the chassis  12  as well. The control board  64  may also be electrically coupled to a receiver  66  located in the chassis  12  for receiving radio signals from a remotely-located radio transmitter (not shown). The radio signals may be received by an external antenna  67  that is positioned on the chassis  12  and coupled to the receiver  66 .  
      Still referring to  FIG. 2 , a gear drive assembly  68  connects the rear drive motor  60  to the rear wheel  26 . The rear drive motor  60  transmits power through the gear drive assembly  68 , which in turn rotates the rear wheel  26  to propel the toy vehicle  10  forward. By enclosing the gear drive assembly  68  and other components within the shell or casing  30 , the toy vehicle  10  is protected against debris that may clog or damage the propulsion drive  54  and gear drive assembly  68 . In other embodiments, the gear drive assembly  68  may be replaced with a drive belt system, a chain drive, or some other means that drivingly couples the propulsion drive  54  to the rear wheel  26 .  
      As shown in  FIGS. 2 and 3 , the steering drive  56  is operatively connected to the front fork  18 , which includes substantially parallel first and second members  76 ,  78  ( FIGS. 4A and 4B ) spaced about the front wheel  24 . The first and second members  76 ,  78  are both connected to one or more fork couplers  80 , which in turn are pivotally connected to the front end  14  of the chassis  12  by a pivot pin  82 . Thus, the front fork  18  pivots about an axis  84 . The axis  84  may also be referred to as a castering axis  84  for reasons discussed in more detail below.  
      Now referring more specifically to  FIGS. 2 and 3 , the operation of the steering drive  56  is shown in greater detail. The steering drive  56  includes the steering servo  62  and a steering arm  90 , which is pivotally connected to the steering servo  62  at pivot point  92 . A link  94  is connected between steering arm  90  and flange  98 , which is fixedly coupled to the second member  78  of the front fork  18 . In operation, the steering servo  62  generates steering outputs that move the steering arm  90 , which in turn moves link  94  either backwards or forwards depending on the desired direction for the toy vehicle  10 . Consequently, when link  94  moves, the front fork  18  pivots about castering axis  84  such that the toy vehicle  10  will turn either left or right relative to longitudinal axis  102 . Alternatively, the link  94  may be pivotally connected to the fork coupler  80  or directly to a portion of the front fork  18 .  
      With reference to  FIGS. 4A and 4B , the front wheel  24  comprises an outer tire  112  that surrounds first and second wheel halves  114 ,  116 . The wheel halves  114 ,  116  are supported on a front axle  118  and may be held together by screws  119  that extend through bores  120  in the first wheel half  114  and into threaded bores  122  ( FIG. 6 ) in the second wheel half  116 . The bores  120  and  122  are positioned around the periphery of the respective first and second wheel halves  114 ,  116  such that the wheel halves  114 ,  116  may be assembled around the flywheel assembly  28 . In other words, the flywheel assembly  28  may be encased between the wheel halves  114 ,  116  and housed within the front wheel  24 .  
      As shown in the figures, the flywheel assembly  28  includes a weighted flywheel  130 , a flywheel plate  132 , and a motor  134 . The weighted flywheel  130  may be coupled to the flywheel plate  132  by screws  136  that extend through bores  138  in the flywheel plate  132  and anchor into corresponding threaded bores  140  ( FIG. 6 ) on the flywheel  130 . The flywheel plate  132  is driven by the motor  134 , which is positioned within a motor mount  144 . The flywheel plate  132  and flywheel  130  are adapted to rotate within the front wheel  24  to create a gyroscopic effect. More specifically, the flywheel plate  132  is adapted to rotate about the front axle  118 , which is fixably attached to the first and second members  74 ,  78  of front fork  18 . Unlike the flywheel plate  132 , the motor mount  144  is operatively connected to the fixed front axle  118  such that it does not rotate about the axle  118 . For example, a hexagonal portion  145  of the front axle  118  may cooperate with a hexagonal bore  146  in motor mount  144  to prevent motor mount  144  from rotating about the axle  118 . Wires  148  electrically couple the motor  134  to the power supply  58  of toy vehicle  10 . As discussed below, the wires  148  may be routed through hollow cavities in the front axle  118  and front fork  18 .  
      In the embodiment shown in  FIGS. 4A and 4B , the motor  134  is drivingly coupled to the flywheel plate  132  by a belt drive system  150 . The belt drive system  150  includes a pulley  152  coupled to the flywheel plate  132  and a pulley  154  connected to the motor  134 . A belt  156  connects pulley  152  to pulley  154  such that when the motor  134  is energized, the flywheel plate  132  and weighted flywheel  130  spin about the front axle  118 . Although only one type of belt drive system  150  is illustrated and described herein, any other similar means may be used in accordance with the present invention to drivingly couple the flywheel plate  132  to the motor  134 . For example,  FIG. 5  shows an alternate configuration of the flywheel assembly  28 . In this configuration, the pulley  152  of  FIGS. 4A and 4B  is replaced with a gear  162 . Similarly, the pulley  154  of  FIGS. 4A and 4B  is replaced with a gear  164 . The gears  162  and  164  are sized such that they engage one another and the belt  156  in  FIGS. 4A and 4B  is eliminated. In other words, when motor  134  is energized, gear  164  drives gear  162  to rotate the flywheel plate  132  and weighted flywheel  130 .  
       FIG. 6  shows the fully assembled front wheel  24  and flywheel assembly  28 . As shown in the figure, the wires  148  may be advantageously routed through hollow cavities  168  and  170  in the front fork  18  and front axle  118 , respectively. Such an arrangement prevents the wires  148  from interfering with the rotation of the front wheel  24  or flywheel  130 . Although only the second member  78  of front fork  18  is shown as having a hollow cavity, the first member  76  may include a hollow cavity as well. In such an embodiment the hollow cavity  170  in the front axle  118  would extend substantially across the entire length of the axle  118  to allow wires to be routed through both the first and second members  76 ,  78  before being coupled to the motor  134 . Alternatively, the wires  148  could be routed on the outside of the front fork  18  and enter the hollow cavity  170  through the end of axle  118 .  
      As shown in  FIG. 7 , the first and second members  76 ,  78  of front fork  18  may be adapted to conduct electricity. In other words, first and second members  76 ,  78  form part of the electrical circuit which provides current to the motor  134 . This arrangement eliminates the need to route wires through hollow cavities in the front fork  18 . Instead, a first set of wires  174  may be used to operatively connect the power supply  58  to a first end  18   a  of front fork  18 , and a second set of wires  176  may be used to operatively connect a second end  18   b  of front fork  18  to the motor  134 . The first and second sets of wires  174 ,  176  are each comprised of a positive wire  180  and a negative wire  182 .  
      Still referring to  FIG. 7 , the first and second members  76 ,  78  are comprised of respective upper shock bodies  184 ,  186  and lower shock shafts  188 ,  190 . At the first end  18   a  of front fork  18 , the positive and negative wires  180 ,  182  are electrically coupled to metal plates  192  located in the shock bodies  184  and  186 . The plates  192  transfer any current to springs  194 , which in turn transfer current to lower shock shafts  188  and  190 . Current may also be transferred through these components in the opposite direction. Accordingly, such an arrangement allows current to flow from the power supply  58  to the motor  134  via the negative wire  182  and second member  78 , and back to the power supply  58  via the positive wire  180  and first member  76 . In order to couple the first set of wires  174  to the power supply  58 , both the positive and negative wires  180 ,  182  at the first end  18   a  of front fork  18  may be routed through the pivot pin  82 .  
      To operate the toy vehicle  10  shown in  FIGS. 1 and 2 , the user places a switch  200  in an “on” position to send power from the power supply  58  to the control board  64 . The power supply  58  may be any suitable power source, such as rechargeable batteries. Upon receiving power, the control board  64  may then energize the motor  134  via the wires  148 . Because the front axle  118  is fixedly connected to the front fork  18  and the motor mount  144  is secured to the front axle  118 , the motor  134  does not rotate about the front axle  118  when activated. Instead, the motor  134  drives pulley  154 , which in turn drives belt  156  and pulley  152  in order to rotate the flywheel plate  132  about the front axle  118 . As discussed below, the rotation of the flywheel  130  with the flywheel plate  132  increases the stability of the toy vehicle  10  by creating a gyroscopic effect when the toy vehicle  10  is in motion.  
      The forward movement of the toy vehicle  10  is controlled by the rear drive motor  60 , which may be any suitable lightweight motor but typically is a battery powered DC motor or a lightweight internal combustion engine. When the rear drive motor  60  is activated, the rear wheel  26  propels the toy vehicle  10  forward and the front wheel  24  freely rotates about the front axle  118 . Because the flywheel assembly  28  is not coupled to the wheel halves  114 ,  116  and tire  112 , the flywheel  130  and front wheel  24  rotate independently of each other. The rotational speed of the flywheel  130  is determined by type of motor  134 , along with the sizes of the belt  156  and pulleys  152 ,  154  (or gears  162 ,  164 ) being used. These components may be chosen in a manner that enables the flywheel  130  to rotate substantially faster than the front wheel  24  during normal operation of the toy vehicle  10 . This rotation of the flywheel  130  creates a gyroscopic effect that helps make the toy vehicle  10  less likely to fall over because of wind or other external forces, including rough terrain. For example, when the toy vehicle  10  encounters a bump along its path of motion, the gyroscopic effect helps keep the vehicle upright and maintain its current path of travel.  
      Additional stability is provided to the toy vehicle  10  by the castering axis  84 . As shown in  FIGS. 1 and 2 , the toy vehicle  10  travels on a surface  210  and the castering axis  84  projects ahead of where the front wheel  24  contacts the surface  210 . Such an arrangement provides a positive caster with a trail  220 , which represents the distance between where the castering axis  84  intersects the travel surface  210  and the contact point of the front wheel  24  with the travel surface  210 . As the toy vehicle  10  travels forward, the castering axis  84  effectively pulls the front wheel  24  along the toy vehicle&#39;s path of motion. Thus, this castering effect or force tends to realign the front wheel  24  with the toy vehicle&#39;s path of motion when the front wheel  24  deviates therefrom due to rough terrain or the like.  
      Although the toy vehicle  10  could function without the assistance of an operator, it is contemplated that an operator will remotely control the toy vehicle  10  by means of a radio transmitter. For example, to initiate forward motion, the operator sends a propulsion signal which is received by receiver  66 . The propulsion signal is then transmitted to the control board  64 , which energizes rear drive motor  60 . Accordingly, the forward motion of the toy vehicle  10  may be controlled by the operator sending an appropriate propulsion signal to the toy vehicle  10 . Similarly, steering signals may also be transmitted by the operator to control the operation of the steering servo  62 . Thus, by using a two-channel transmitter the operator can remotely and independently control both the forward motion and direction of the toy vehicle  10 .  
      The motor  134  may be controlled with or without use of the remote radio transmitter. For example, the toy vehicle  10  may be adapted such that the motor  134  is activated whenever the switch  200  is placed in the “on” position. In such an embodiment the motor  134  operates independently of the two-channel transmitter and rotates the flywheel  130  about the front axle  118 , even when the toy vehicle  10  is not in motion. Alternatively, the motor  134  may be operatively connected to the receiver  66  such that the motor  134  becomes operative when the receiver  66  receives a propulsion signal. By only activating the motor  134  when the toy vehicle is in motion, the toy vehicle helps prolong the operable life of power supply  58  by utilizing less energy over a given period of time. In a further embodiment, the control board  64  may have a timing mechanism adapted to deactivate the motor  134  after a predetermined time period of inactivity by the propulsion drive  54 . Such an arrangement helps prolong the operable life of power supply  58  as well.  
      While the present invention has been illustrated by the description of one or more embodiments thereof, and while the embodiments have been described in considerable detail, they are not intended to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and method and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the scope or spirit of the general inventive concept.