Patent ID: 8915527

Claim:
A method of taking a target workpiece out of a plurality of workpieces by using a robot including a robot hand, the robot hand including a chuck supported by a hand main body via an elastic member, the chuck including at least two fingers of rigid material and being movable relative to the hand main body, the method comprising: moving the hand main body toward the target workpiece so that the fingers apply a pre-pressure against the target workpiece until the elastic member is compressed by a predetermined amount, wherein said pre-pressure is applied against the target workpiece when the fingers are not holding the target workpiece; opening the chuck in a state where the fingers apply the pre-pressure against the target workpiece, so that a resultant force of opening the chuck and a restoring force of the compressed elastic member causes the fingers to respectively enter positions laterally close to the target workpiece; closing the chuck upon the fingers respectively entering the position, to cause the fingers to hold the target workpiece; and taking the target workpiece out of the plurality of workpieces in a state where the chuck is closed.