PROCEDIMENTO PER LA FORMAZIONE DI PACCHI DI SEGNATURE ED IMPILATRICE PER L'ESECUZIONE DEL PROCEDIMENTO

A method of forming a packet of signatures is proposed, comprising a known step of depositing onto the feeding belt of the stacker signatures from the folding machine, and which includes a transport step of the groups of overlapping signatures to a stacking station, a step during which the presence or absence of signatures is detected upstream of the stacking station, with the issuing of a control signal active on detent means for the stacking, and a stacking step with a following step of removal of said detent means and a step of removal of the formed stack. It is, preferably, also included a step of detecting the presence or absence of signatures downstream of the stacking station, with the issuing of a corresponding control signal active on the stacking detent means. The stacker implementing said method comprises a stacking station, stacking detent means movable to a stacking station, or detent position, and away therefrom, sensor means for detecting the presence or absence of signatures upstream of the stacking station, as well as sensor means for detecting the presence or absence of signatures downstream of the stacking station.