Patent ID: 8235377

Claim:
A mailpiece unstacker device comprising an unstacker head, and a motor-driven feed magazine for moving mailpieces in a stack and on edge in a certain direction towards said unstacker head, wherein said unstacker head is suitable for separating a first mailpiece from the stack and for driving said first mailpiece in a direction that is transverse to said direction in which the stack of mailpieces move, and wherein said mailpiece unstacker device further comprises a first material sensor suitable for delivering a first signal indicating that a current mailpiece of the stack has a cover made of a plastics material; a second material sensor suitable for delivering a second signal indicating that the current mailpiece includes a metal material; and a control unit for causing said feed magazine and said unstacker head to operate in a plurality of operating modes specific to the presence or to the absence of a plastics material and a metal material in the mailpieces to be unstacked, said control unit being arranged to choose an operating mode from among said plurality of operating modes as a function of the first and second signals.