Tracking apparatus in conveyorized transport system

摘要

A tracking arrangement for a conveyorized transport system of the type in which coded workpiece carriers are routed by a switching mechanism from a main rail to an entry end of a subsidiary loop and then returned to the switching mechanism via a discharge end of the subsidiary loop, the entry end of the subsidiary loop being located downstream of the discharge end relative to the general direction of carrier movement on the carrier rail. The tracking arrangement comprises a sensor which reads the codes on the carriers while the carriers are located on the switching mechanism so that the codes may be read shortly before a carrier enters into a subsidiary loop and shortly after the carrier exits from a subsidiary loop. A second subsidiary loop may be provided directly across the main rail of the aforesaid subsidiary loop, the switching mechanism also servicing the second subsidiary loop, and the sensor reading the codes on the carrier shortly before the carriers enter into the second subsidiary loop and exit from the second subsidiary loop.