Patent ID: 8177228

Claim:
An apparatus for monitoring the singling of sheet material, comprising a singler, a drive and a control device arranged to monitor and control the singler; a plurality of sensors adapted to monitor and output signals for place, time, orientation and state of the singled sheet material immediately after the singling; wherein said plurality of sensors comprise three sensors which are disposed immediately after the singler, two of the sensors being disposed at opposite edge areas of the width provided for the transport of the sheet material and a third sensor being disposed between the two sensors, wherein signals of the plurality of sensors are evaluated by the control device with respect to the point of time of the presence or absence of sheet material at the plurality of sensors, and wherein the state of the singled sheet material is determined by the third sensor, wherein signals of the third sensor are evaluated by the control device with respect to the presence of one or a plurality of pieces of sheet material; wherein the plurality of sensors are disposed substantially along a line extending perpendicular to a transport direction, which is located immediately after the singler, but at a maximum in a distance in which singled sheet material is still clamped by the singler; wherein the control device is arranged to determine a correct singling of sheet material, if the signals of the third sensor and at least one of the two sensors disposed at opposite edge areas are present at the control device within a predetermined time difference, and if the signal of the third sensor for determining the presence of one or a plurality of pieces of the sheet material indicates the presence of a single piece of sheet material; and wherein the control device is arranged to determine a faulty singling of sheet material if the signals of the three sensors are not present at the control device within a predetermined time difference, or if the signal of the third sensor for determining the presence of one or a plurality of pieces of sheet material indicates the presence of a plurality of pieces of sheet material.