Postal sorting machine including nipping conveyor means, and a method of using the machine

A postal sorting machine comprising:

• an unstacker suitable for putting mailpieces on edge;
• address recognition means for recognizing the addresses of the mailpieces;
• a conveying zone for conveying the mailpieces by nipping them, which zone is made up of an unstacking zone extending from the unstacker, and of a sorting zone having a plurality sorting outlets, distributed from an upstream sorting outlet adjacent to the unstacker, to a downstream sorting outlet;
• a recirculation zone interconnecting the downstream sorting outlet and the upstream sorting outlet, said recirculation zone co-operating with the unstacking zone to define a point of confluence situated between the unstacker and the upstream sorting outlet;
• and
• synchronization means suitable for synchronizing the movements firstly of the “unstacked” mailpieces traveling between the unstacker and the point of confluence, and secondly of “recirculated” mailpieces traveling in the recirculation zone, said synchronization means including detection means for detecting the presence of at least one recirculated mailpiece, and control means suitable for acting on the unstacker in response to information transmitted by the detection means.