Substrate transport apparatus with multiple movable arms utilizing a mechanical switch mechanism

A substrate transport apparatus comprising:

• a drive section having at least two independently controllable motors;
• an articulated arm including a first SCARA arm being configured to extend in a first direction and a second SCARA arm being configured to extend in a second direction substantially opposite the first direction, each of the first and second SCARA arms having:
• a shoulder axis,
• a wrist axis,
• but one respective chain of links, each link in the but one respective chain of links being serially coupled between the shoulder axis and the wrist axis so that each link is coupled to each other link in the but one respective chain of links, and
• an end effector, for holding a substrate thereon, coupled to the wrist axis and supported by the but one respective chain of serially coupled arm links;
• and
• a coupling operably coupling each of the first and second SCARA arms to each other and to a respective one of the at least two independently controllable motors substantially continuously;
• the coupling being configured so that relative movement between the at least two independently controllable motors causes a change in relative angular orientation between the end effector of the first SCARA arm and the end effector of the second SCARA arm and effects extension and retraction of a respective one of the first and second SCARA arms substantially independent of each other.