Patent ID: 7407208

Claim:
A robot hand, comprising: a main frame; a plurality of finger mechanisms connected to the main frame and including a plurality of joint portions; and a plurality of drive portions driving the joint portions, wherein the drive portions comprise a plurality of drive elements with different outputs, and each of the drive elements of the drive portions is capable of being expanded or contracted in accordance with an applied electrical signal, and wherein: when F is a grasping force operating on a grasped object; L 1 is a distance from the center of the joint portion to the point of action of the grasping force; L 2 is a distance from the center of the joint portion to the point of action of the output of the drive elements; F 1 is a force preventing a rotational driving of the joint portion; Fa is the output of the drive element with the weaker output; and Fb is the output of the drive element with the stronger output; then Fa and Fb can be respectively expressed as Fa=F 1 , and Fb=F 1 +F 2, where F 2 =F×L 1 /L 2).