Method and arrangement for detecting overlapping flat mailpieces

A method for detecting overlapping flat mailpieces in a transport path for mailpieces that are transported vertically in succession, comprising the following steps:

• arranging at least two transport stages successively in the transport path, wherein each transport stage has a nominal speed, wherein the nominal speed of a following transport stage in a transport direction is in each case higher than the nominal speed of the transport stage preceding it,
• measuring a speed of the transported mailpieces by scanning said items in front of a following transport stage for a maximum distance that is shorter than a shortest agreed mailpiece length by means of two sensors that are arranged on either side of the transport path,
• evaluating measured results if a sensor measures a speed that deviates only slightly by a defined small value from the nominal speed of the following transport stage, and
• detecting an overlap if simultaneously measured speeds of the two sensors are different and a smaller measured speed deviates from a greater speed by a defined value.