Patent ID: 7762361

Claim:
A ground-support apparatus ( 110 ) comprising: an omni-directional vehicle capable of rotation about a vertical axis ( 116 ) that passes through said omni-directional vehicle, said omni-directional vehicle including a frame ( 114 ) and first and second drive wheels ( 112 ) coupled to said frame ( 114 ), each of said drive wheels ( 112 ) capable of independent forward and rearward rotation about a horizontal axis ( 118 ) that intersects said vertical axis ( 116 ), and a power source ( 122 ) coupled to said first and second drive wheels ( 112 ); a material handling mechanism ( 160 ) having a material handling mechanism axis ( 117 ) and coupled to said omni-directional vehicle so that said material handling mechanism axis ( 117 ) lies in a first radial direction from said vertical axis ( 116 ); and a counterweight ( 174 ) having a counterweight axis ( 119 ) and coupled to said omni-directional vehicle so that said counterweight axis ( 119 ) lies in a second radial direction opposite said first radial direction from said vertical axis ( 116 ), said counterweight ( 174 ) being movable with respect to said vertical axis ( 116 ) along said second radial direction so that said counterweight ( 174 ) can compensate for varying load forces on said material handling mechanism ( 160 ).