Abstract: Successive packets of cigarettes or the like are monitored to ascertain the integrity or absence of integrity of their outer envelopes by conveying them across at least one curtain of radiation so that a packet having an improperly glued flap or tuck or label or an analogous defect affecting the acceptability of its outline intercepts a greater amount of radiation than a packet having an outline matching that of a prototype. First signals denoting the amount of radiation intercepted by successive packets are compared with a reference signal denoting the amount of radiation intercepted by the prototype and, when the difference between a first signal and the reference signal is outside of a permissible range, the corresponding packet is segregated from other packets.

Abstract: The operation of a driving system for a cigarette packing machine, wherein the driving system has a rotary main drive and several slave drives electrically connected to the main drive, is controlled in such a way that any selected slave drive can be disconnected from, decelerated to zero speed, accelerated from zero speed to normal speed and reconnected into the drive system in predetermined angular positions of the main drive. Each slave drive transmits motion to one or more movable parts or units of the packing machine in such a way that the movable parts do not clash even though they are movable and do move relative to each other.