US Patent 7753638 Robot hand having swaying mechanism in library apparatus

A library apparatus includes cells. A positioning mechanism serves to position a carriage relative to the cells within an operating region adjacent to a standby region. A transporting mechanism drives the carriage toward the standby region. A swaying mechanism allows grasping fingers on the carriage to go around an object lying on the movement path of the grasping fingers when the transporting mechanism carries the carriage to the standby region. The grasping fingers acts to hold an object within the cell. If the positioning mechanism malfunctions, the transporting mechanism transfers the carriage to the standby region. Even if an object exits on the movement path of the grasping finger, the carriage is allowed to keep moving because the swaying mechanism allows the grasping finger or fingers to sway around the object on the movement path. The carriage thus reliably reaches the standby region.