Mobile base having leg assemblies with two wheels

A mobile base for moving about a surface, comprising:

• housing means;
• universal driving and steering assembly means arranged in said housing means for providing a driving torque and a steering torque, having main drive shaft means for providing the driving torque, and having main steer shaft means for providing the steering torque;
• and
• at least one wheel assembly, comprised of:
• steering column means being rotationally coupled to said housing and said main steer shaft means, for providing a steering column force in response to the steering torque;
• concentric drive shaft means for providing concentric drive shaft force including a first drive shaft force and a second drive shaft force in response to the driving torque, being rotationally coupled to the housing and said main drive shaft means, being coaxially arranged with respect to said steering column means, and having first drive shaft means and second drive shaft means for providing the first drive shaft force, said first drive shaft means coaxially arranged with respect to said second drive shaft means for providing the second drive shaft force;
• and
• dual wheel means being coupled to the steering column means, having a first wheel being rotationally coupled to the first drive shaft means for rotating in response to the first drive shaft force, and having a second wheel being rotationally coupled to the second drive shaft means for rotating in response to the second drive shaft force.