Conveyor carriage control system

Abstract

A system for controlling the movement of carriages in a conveyor system is disclosed in which individually powered carriages are controlled so as to stop a carriage at a designated position on the conveyor rail. Electrical contact wires extend along the conveyor rail and are electrically connected to controller units on each of the carriages by electrical contacts sliding along the electrical contact wires. Certain ones of the electrical contact wires have electrical discontinuities which define boundaries of first and second zones. The electrical discontinuities form a normally open electrical circuit with the controller units of each of the carriages, thereby keeping such controller units in the inoperative or 'off' position. In this position of the controller unit, the power unit of each of the individual carriages drives the carriage along the conveyor rail. When the electrical circuit of the electrical contact wires is completed in a first zone, such as by the presence of a stopped carriage or other obstruction, the controller unit of a carriage entering the adjacent second zone will be actuated by this completed electrical circuit and will stop the carriage before it encounters the stopped carriage or other obstruction.