US Patent 8733478 Camera crane mobile base

A mobile base for a camera crane includes a front left drive motor assembly, a front right drive motor assembly, a rear left drive motor assembly, and a rear right drive motor assembly, attached to a chassis. Each drive motor assembly may include an electric motor linked to an axle via a gear reduction and at least one wheel on the axle. A middle left drive motor assembly and a middle right drive motor assembly may each also include an electric motor linked to an axle via a gear reduction, at least one wheel on the axle, and a spring suspension assembly attached to the chassis and supporting the axle. An electrical power supply on the chassis may be linked to each of the electric motors.