An automated transport system that travels on the overhead track and "directly" accesses the load port of the stocker or process equipment by the belt driven hoisting mechanism. "OHT" is the abbreviation for Overhead Hoist Transfer. This is widely recognized as the main transport system for 300mm FAB and next generation FABs and is currently used not only for intra-bay transport but also inter-bay or factory wide transport.
Muratec's OHT systems are protected by one or more patents including without limitation: US Patent Nos. 6183184,7165927,7441999,7771153, and 8197172. Other patents are pending.