Patent ID: 7734375

Claim:
A robot leg mechanism comprising: a leg; a hip connected to the leg and configured to abduct and adduct the leg, the hip including: a rotatable frame portion, a pair of coupler gears, and an output gear engaging the pair of coupler gears; a linkage configured to rotate the leg along a predetermined path, the linkage including: a crank rotatably connected to the leg and driven by the output gear when the pair of coupler gears are driven in opposite directions and at the same speed to rotate the leg along the predetermined path, a first member pivotably connected to the leg, and a second member pivotably connected to the first member and connected to the frame portion; and a shaft coupled to the pair of coupler gears and the rotatable frame portion, the frame portion rotating about the shaft when the pair of coupler gears are driven in the same direction and at the same speed to abduct and adduct the leg; the coupler gears rotatable in the same or opposite directions at different speeds to both rotate the frame portion and turn the output gear to abduct and adduct the leg while rotating the leg along the predetermined path.