US Patent 7192241 Substrate conveyer robot

A substrate conveyer robot inserts and removes a substrate to and from a an arbitrarily positioned container. A base is rotatably driven by a first motor which defines a pivotal center. A first spindle is rotated by a second motor independent of rotation of the base, is positioned coaxially with the pivotal center, and one end of a first arm is attached to the first spindle. A second spindle on the other end of the first arm is rotated by a gear ratio 2:1, and one end of a second arm is attached to the second spindle. A third spindle is carried on the other end of the second arm and is rotated by a gear ratio 1:2. One end of a third arm is attached to the third spindle, and a hand for holding a substrate is attached on the other end of the third arm.