Gearbox used in wheel assemblies with variable level of vibration

A wheel assembly of a toy vehicle offering pull back features with adjustable, variable level of vibration, comprising:

• a case unit, where in the case unit is formed at a shape of circle or a wheel;
• a wheel axle, where in the wheel axle allows the case unit to rotate;
• and
• a gearbox unit movably attached inside the case unit, comprising:
• a coil spring that is retractable, wherein:
• the coil spring is contactless with the wheel axle directly, or indirectly through gears or shafts;
• the coil spring is wind up when the wheel assembly is pulled backward;
• and
• when released, the coil spring unwinds and propels the toy vehicle forward, as energy stored during pull back gets released during forward motion;
• an output shaft producing rotational motion when the coil spring unwinds from its retracted position, wherein the output shaft:
• is contactless with the wheel axle directly, or indirectly through other gears or shafts;
• is positioned inside the wheel assembly at a distance away from the wheel axle or center point of the wheel assembly;
• and
• causes the wheel assembly to rotate at a pivotal point other than the center point of the wheel assembly, resulting the wheel assembly to rotate at a varying vertical axis relative to ground, which causes an effect of bumpy rotational movement when the wheel assembly rotates;
• and
• a handle allows the gearbox unit to be placed on a different location within the car assembly unit, wherein during rotation of the output shaft, the wheel assembly would rotate and vibrate in a different manner.

A toy vehicle offering pull back features with adjustable, variable level of vibration, comprising:

• a wheel consisting of a wheel assembly comprising:
• a case unit, where in the case unit is formed at a shape of circle or a wheel;
• a wheel axle, where in the wheel axle allows the case unit to rotate;
• and
• a gearbox unit movably attached inside the case unit, comprising:
• a coil spring that is retractable, wherein:
• the coil spring is wind up when the wheel assembly is pulled backward;
• and
• when released, the coil spring unwinds and propels the toy vehicle forward, as energy stored during pull back gets released during forward motion;
• an output shaft producing rotational motion when the coil spring unwinds from its retracted position, wherein:
• the output shaft:
• does not make contact to the wheel axle;
• is positioned inside the wheel assembly at a distance away from the wheel axle or center point of the wheel assembly;
• and
• causes the wheel assembly to rotate at a pivotal point other than the center point of the wheel assembly, resulting the wheel assembly to rotate at a different axis relative to ground, which causes an effect of bumpy rotational movement when the wheel assembly rotates;
• and
• a handle allows the gearbox unit to be placed on a different location within the car assembly unit, wherein during rotation of the output shaft, the wheel assembly would rotate and vibrate in a different manner.