Patent ID: 8550632

Claim:
A mobile base, comprising: first and second side tubes joined to first and second end tubes forming a substantially rectangular chassis; first, second, third and fourth drive motor assemblies at first, second, third and fourth corners of the rectangular chassis, respectively, with each drive motor including a structural fitting and a motor housing pivotally attached to the structural fitting, with the motor housing including an electric motor linked to an axle via a gear reduction, and at least one wheel attached to the axle: the structural fitting of the first and second drive motor assemblies slidably positioned into opposite ends of the first end tube, and the structural fitting of the third and fourth drive motor assemblies slidably positioned into opposite ends of the second end tube; an electrical power supply on the chassis separately connected to each of the electric motors through a controller allowing separate control of each motor; a column pivotally attached to the chassis: one or more lateral actuators attached to the chassis and to opposite sides of the column, for pivoting the column laterally, and one or more longitudinal actuators attached to the chassis and to the column, for pivoting the column longitudinally, with the column having first height when the longitudinal actuators are at a first position, and the column having a second height when the longitudinal actuators are at a second position, and with the second height less than 70% of the first height.