US Patent 10518838 Frame of a vehicle with front wheels

A frame of a vehicle includes a front fork unit pivotably connected to a head tube of a vehicle body mechanism, a crank axle disposed on the front fork unit for two front-wheel cranks to be pivoted thereon. Two front wheels are pivotably disposed on the cranks, respectively. A front-wheel counteracting mechanism is pivotably connected between each of the cranks and the front fork unit to transmit an impact force to the cranks so as to cause opposite upward and downward movements of the front wheels to thereby keep the front wheels in contact with the ground and to render movement of the vehicle steady and safe.