Patent ID: 6883641

Claim:
A ground-movable carriage for supporting spacedly over ground a liftable platform with an extendable scissor linkage assembly, said carriage including: a) a rigid main frame, defining a front portion, a rear portion, and a middle portion intermediate said front portion and said rear portion; b) a first pair of ground-engageable front pivotal casters, rotatably mounted to said main frame front portion in laterally spaced apart fashion; c) a second pair of ground-engageable rear pivotal casters, rotatably mounted to said main frame rear portion in laterally spaced fashion; d) a ground-engageable omnidirectional drive wheel assembly, mounted for relative movement to said main frame middle portion; and c) a power unit, operatively connected to said drive wheel assembly and powering said drive wheel assembly in moving said carriage rollingly over ground; wherein said drive wheel assembly can provide full turn rotation of said carriage without fore and aft motion; wherein said drive wheel assembly includes a first wheel axle and a second wheel axle, each of said first wheel axle and second wheel axle being independently articulated to said carriage main frame by first pivot mount system and by a second pivoted suspension system; and further including a first reduction gear assembly, connected to said first wheel axle, and a second reduction gear assembly, connected to a said second wheel axle; and wherein said power unit includes a first motor, connected to said first wheel axle and cooperating with said first reduction gear assembly, and a second motor, connected to said second wheel axle and cooperating with said second reduction gear assembly; at least one of said first motor and second motor providing reversible torque output.