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'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 '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 '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.
In one embodiment, the flywheel is driven by a motor and rotates independently of the front wheel to generate a gyroscopic effect while the toy vehicle is moving. 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.
In another embodiment, an engagement mechanism is housed within and operatively coupled to the front wheel so as to be driven thereby. The engagement mechanism is configured to rotate the flywheel such that a separate motor, such as the one used in the other embodiment, is not required. More specifically, the engagement mechanism rotates the flywheel in a first direction when driven by the front wheel in the first direction, but allows the flywheel to continue to rotate in the first direction independently of the front wheel after the front wheel decelerates in the first direction. The flywheel may even continue to rotate in the first direction when the front wheel stops rotating in the first direction.
In one embodiment, the engagement mechanism includes a first component driven by the front wheel about a front axle of the toy vehicle and a second component coupled to the flywheel. The first component engages the second component when rotated in the first direction so that the flywheel also rotates in the first direction. When the front wheel and first component decelerate in the first direction, the second component ceases engaging the first component such that the flywheel continues to rotate in the first direction independently of the front wheel. The first and second components may also be configured to allow the front wheel to rotate in a second direction without the first component engaging the second component. To this end, the first and second components act as a one-way engagement mechanism.
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 one embodiment of a toy motorcycle according to the 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;
FIG. 7 is a cross-section view similar to FIG. 6 showing an alternate front fork design;
FIG. 8 is a side view similar to FIG. 1 showing a toy motorcycle with an engagement mechanism and flywheel according to an alternative embodiment of the invention;
FIG. 9 is an exploded perspective view of the front wheel of the toy motorcycle shown in FIG. 8;
FIGS. 10A-10C are schematic views illustrating the operation of the engagement mechanism shown in FIG. 8;
FIGS. 11A and 11B are schematic views illustrating the operation of an engagement mechanism according to another embodiment of the invention; and
FIGS. 12A and 12 are schematic views illustrating the operation of an engagement mechanism according to yet another embodiment of the invention.
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 18a of front fork 18, and a second set of wires 176 may be used to operatively connect a second end 18b 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 18a 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 18a 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's path of motion. Thus, this castering effect or force tends to realign the front wheel 24 with the toy vehicle'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.
FIG. 8 illustrates an alternative embodiment of a toy vehicle 310 having a flywheel 312 configured to rotate within a front wheel 314 to generate a gyroscopic effect. The components of the toy vehicle 310 other than those housed within the front wheel 314 may be the same as those discussed above with reference to FIGS. 1-7. Accordingly, like reference numbers are used in FIG. 8 to refer to like elements from the embodiment shown FIGS. 1-7.
Rather than including a separate motor for rotating the flywheel 312, the toy vehicle 310 includes an engagement mechanism 316 housed within the front wheel 314 for rotating the flywheel 312. As shown in FIG. 9, the engagement mechanism 316 generally includes a first component 318 operatively coupled to the front wheel 314 and a second component 320 coupled to the flywheel 312. The front wheel 314 includes a wheel housing 326, a cap 328 secured to the wheel housing 326 by screws 330, an outer tire 332 surrounding the wheel housing 326, and a front axle 334 fixedly connected to the front fork 18 (FIG. 8) and rotatably supporting the wheel housing 326 and cap 328. It will be appreciated, however, that the front wheel 314 may alternatively comprise first and second wheel halves (not shown) surrounded by the outer tire 332 so as to be constructed in a similar manner as the front wheel 24 (FIG. 4A).
As shown in FIG. 9, the first component 318 is a generally circular member having a first semi-circular wing or arcuate portion 338 offset from a second semi-circular wing or arcuate portion 340. The second component 320 is a generally cylindrical boss secured to or integrally formed with the flywheel 312 and defines a socket 342 for receiving the first component 318. First and second friction elements 344, 346, which may be spherical balls, are received within the socket 342 between an outer rim 348 and the first component 318. The first and second friction elements 344, 346 enable the first component 318 to engage the second component 320 to rotate the flywheel 312, as will be described in greater detail below.
The front wheel 314 further includes a gear assembly 354 housed within a recess 356 defined by the wheel cap 328. The gear assembly 354 is retained in the recess 356 by a gear plate 358 secured to the wheel cap 328 by screws 360. Although a wide variety of configurations are possible, the gear assembly 354 shown in FIG. 9 includes a planetary gear 362, a central gear 364, and first, second, and third satellite gears 366, 368, 370. The planetary gear 362 is fixedly attached to the front axle 334 by a set screw (not shown) or the like such that it remains stationary with the front axle 334 when the front wheel 314 rotates. The first, second, and third satellite gears 366, 368, 370 are rotatably mounted on respective first, second, and third axles 372, 374, 376, which engage the gear plate 358 via respective first, second, and third througholes 378, 380, 382. Thus, when the rear drive motor 60 (FIG. 2) is activated so that the toy vehicle 310 moves forward and causes the front wheel 314 to rotate about the front axle 334, the gear plate 358 causes the satellite gears 366, 368, 370 to rotate as well. In turn, the satellite gears 366, 368, 370 rotate the central gear 364, which extends through a central opening 384 in the gear plate 358 and engages the first component 318 of the engagement mechanism 316.
As a result of this arrangement, the first component 318 is operatively engaged to the front wheel 314 so as to be driven thereby. Advantageously, the size of the planetary gear 362, central gear 364, and satellite gears 366, 368, 370 are selected such that one revolution of the front wheel 314 causes several revolutions of the first component 318. For example, the first component 318 may rotate between about five to ten times for each rotation of the front wheel 314. Additionally, the gear plate 358 confronts the second component 320 of the engagement mechanism 316 when the front wheel 314 is assembled to retain the first component 318 and first and second friction elements 344, 346 within the socket 342.
FIGS. 10A through 10C illustrate the operation of the engagement mechanism 316 in further detail. When rotated in a first direction 388, the first component 318 causes the first friction element 344 to frictionally engage the first arcuate portion 338 and outer rim 348 so as to become wedged therebetween. The second friction element 346 likewise frictionally engages the second arcuate portion 340 and the outer rim 348 so as to become wedged therebetween. This positive engagement enables the first component 318 to rotate the second component 320 and flywheel 312 in the first direction 388. This positive engagement differs from other engagement mechanism where one member may slip along another member before full engagement occurs, such as in a traditional centrifugal clutch. As discussed above, the first component 318 advantageously rotates at a faster rate than the front wheel 314 because of the gear assembly 354. Consequently, the flywheel 312 rotates at a faster rate as well to generate gyroscopic forces that stabilize the toy vehicle 310.
When the front wheel 314 and first component 318 decelerate in the first direction 388, the first and second friction elements 344, 346 release from engagement with the respective first and second arcuate portions 338, 340 and the outer rim 348 of the second component 320. This allows the second component 320 and flywheel 312 to continue rotating in the first direction 388 independently of the front wheel 314. Indeed, as shown in FIG. 10B, the second component 320 and flywheel 312 may even continue to rotate in the first direction 388 when the front wheel 314 is stopped. The configuration of the first component 318 ensures that the first and second friction elements 344, 346 remain loosely positioned within the socket 342 so as to cause minimal interference with the continued rotation of the second component 320. In particular, the continued rotation of the second component 320 faster than the first component 318 urges the first friction element 344 toward a planar surface 390 and the second friction element 346 toward a planar surface 392 anytime the first and second friction elements 344, 346 contact the outer rim 348. The planar surfaces 390, 392 of the first component 318 extend toward the outer rim 348 in a direction substantially perpendicular to a tangent (not shown) of the outer rim 348. Thus, the first and second friction elements 344, 346 do not become wedged between the planar surfaces 390, 392 and the outer rim 348.
The same relationship holds true when the first component 318 is rotated in a second direction 394, as shown in FIG. 10C. In this situation, the planar surfaces 390, 392 come into contact with the respective first and second friction elements 344, 346, which simply roll within the socket 342 so as to not impede the rotation of the first component 318. This occurs whether the flywheel 312 is rotating in the first direction 388 or not. To this end, the engagement mechanism 316 acts as a one-way engagement mechanism.
The first and second friction elements 344, 346 shown in FIGS. 8-10C are spherical balls. It will be appreciated, however, that many other shapes and configurations are possible. For example, the first and second friction elements 344, 346 may alternatively be cylindrical discs (not shown) retained in the socket 342 by the gear plate 358. Additionally, although first and second friction elements are shown in the figures, it will be appreciated that only a single friction element is required to cause engagement between the first and second components 318, 320. Alternatively, the first and second components 318, 320 may be configured to cooperate with more than two friction elements.
FIGS. 11A and 11B illustrate an engagement mechanism 410 according to an alternative embodiment. In this embodiment, the first component is a ratchet wheel 412 having a plurality of projections 414 along its outer perimeter and the second component is a ratchet tab 416 pivotally connected to the flywheel 412. The ratchet tab 416 positively engages one of the projections 414 when the ratchet wheel 412 is rotated in the first direction 388 (FIG. 11A). There is no slippage between the ratchet tab 416 and projections 414 during the engagement process. To facilitate this engagement, the ratchet tab 416 may be normally biased against the ratchet wheel 412. As a result of this arrangement, the ratchet wheel 412 rotates the flywheel 312 when driven in the first direction 388 by the front wheel 314. When the front wheel 314 and ratchet wheel 412 decelerate in the first direction 388, the flywheel 312 is able to continue rotating in the first direction 388 independently of the ratchet wheel 412 because the ratchet tab 416 is simply deflected by (rather than engaged by) the projections 414 as it passes over them. As shown in FIG. 11B, the flywheel 312 may continue to rotate in the first direction 388 even when the front wheel 314 is stopped. The ratchet wheel 412 and ratchet tab 416 may or may not be positioned in a socket 418 similar to the socket 342 in FIGS. 8-10C.
FIGS. 12A and 12B illustrate an engagement mechanism 430 according to yet another embodiment. In this embodiment, the first component is a paw wheel 432 having one or more arms 434 extending therefrom and the second component is a cylindrical boss 436 coupled to the flywheel 312. The cylindrical boss 436 defines a socket 438 for receiving the paw wheel 432 and includes a plurality of notches 440 shaped to cooperate with the arms 434 of the paw wheel 432. In particular, when the paw wheel 432 is rotated in the first direction 388 (FIG. 12A), each arm 434 positively engages an engagement surface 442 on one of the notches 440 so that the cylindrical boss 436 and flywheel 312 are rotated in the first direction 388 as well. There is no slippage between the ratchet tab 416 and projections 414 during the engagement process. When the paw wheel 432 decelerates in the first direction 388 (FIG. 12B), the notches 440 release from engagement with the arms 434 to allow the cylindrical boss 436 and flywheel 312 to continue to rotate in the first direction 388 independently of the front wheel 314 and paw wheel 432. The notches 440 may include guide surfaces 444 that contact the arms 434 during this relative rotation, but the guide surfaces 444 simply cause the arms 434 to flex inwardly so as to cause minimal interference with the relative rotation. To this end, the arms 434 may be resilient.
The design of the embodiments of FIGS. 8-12B assists the toy vehicle right itself, i.e, standup, from a tipped over position without user intervention, especially in the situation when the flywheel is stopped or slowly spinning. As the toy vehicle attempts to move forward from a dead stop, the front wheel and the stopped or nearly stopped flywheel resists being rotated. As the flywheel resists rotating, the front wheel is able to overcome the caster affect and turn sharper than it normally would. Consequently, the bike will turn in a tighter radius and create enough centrifugal force in the toy vehicle to cause the toy vehicle to lift off its side and onto two wheels quicker than without the resistance of the flywheel.
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.
Patent Application
20070207699
