US Patent 7621392 Conveyor carousel with distributed drive system

A carousel according to the invention uses a number of smaller, less expensive drive units at different locations along the carousel path in place of a single larger drive unit of comparable capacity. Closed loop control according to the invention allows individual drives to be de-energized when the power requirements do not demand their usage. When not energized, the drives may be disengaged from the chain, such as by way of a linear actuator as described hereafter. Benefits of such a system include reduced mechanical costs, longer drive life, better redundancy/higher availability, correct drive power, lower energy use, closed loop system monitoring and reduced collateral damage.