Abstract: An improved motive structure for transporting workpieces (wafers, chip, packages, etc.) between processing stations or tools in a manufacturing operation. The structure includes a first circular crankshaft assembly connected to center axles disposed at right angles to the transport motion. A second such crankshaft assembly is located some distance along the path of motion. Three driverods are connected between the first and second crankshaft assemblies, each affixed 120.degree. apart on the circular crankshafts so that each driverod is moved upward, then forward along the transport direction, then downward and backward to its original position as the crankshafts go through a complete 360.degree. rotation. The structure is disposed beneath transport rails which hold movable containers for holding the workpieces. As a driverod moves up and forward, it contacts a spring-loaded element on the movable container and drives it forward by friction contact.