Abstract: A conveyor or case drive mechanism includes a continuous chain loop having two or more drive motors positionally spaced there along. A sensor is associated with the motors for sensing slack in the chain at the associated motor. When a predetermined amount of slack in the chain is no longer present at the motor, the sensor presents an output signal which, through a speed control device, increases the rotational speed of the associated motor until generation of the requisite slack in the chain has been achieved. Each motor in the chain drive loop has a sensor structure associated with it such that each motor provides a motive force to the chain.