Zoned transport conveyor with automatic zone start-up and shut-down

Abstract

A zoned transport conveyor includes a drive roller and a series of driven rollers for each zone. A motor is interconnected with the drive roller for imparting rotation to the drive roller, which in turn is drivingly engaged with the driven rollers such as through a series of belts. Introduction of a load onto the zone results in rotation of an upstream one of the driven rollers, which is transferred through the drive arrangement to the drive roller. Rotation of the drive roller results in rotation of an output member associated with the motor, which is detected by a series of sensors associated with the motor and which provides and input to a motor control circuit. The motor control circuit includes a processor for controlling operation of the motor, and the processor functions to initiate operation of the motor when inertial rotation of the motor output member is detected. The processor functions to continue operation of the motor for a predetermined time period sufficient to allow a load to be discharged from the zone, after which operation of the motor is stopped so as to stop operation of the zone until introduction of a subsequent load. A bus spans the length of adjacent zones, and provides power supply and ground to the motor and to the control circuit. The bus may also carry a stop line providing a stop input to the control circuit, and the processor is responsive to a stop signal from the stop line so as to initiate dynamic braking of the motor to quickly stop advancement of any loads carried by the zone.