Method for automated filling of a mail tray from a vertical stacker

A method for controlling operation of an automated mail tray filler for taking envelopes from a vertical stacker output of an inserter machine and placing them in mail trays, the vertical stacker arranged to provide a vertical stack of finished envelopes on a long vertical stacker table, the vertical stacker table being capable of transporting the vertical stack away from an inserter output where envelopes are added to the vertical stack, the movable mail tray filler being movable in parallel next to the vertical stacker table and including a take-away feeder arranged to withdraw envelopes from a distal end of the vertical stack in a sideways direction, a pressure sensor positioned proximal to the take-away feeder to detect a pressure of the vertical stack of envelopes against the take-away feeder, the method comprising:

• determining whether a predetermined trigger pressure has been reached at the pressure sensor;
• determining whether the mail tray filler is in a pause mode;
• determining whether a current position of the take-away feeder is closer to an upstream end of the vertical stacker than a predetermined minimum optimized distance;
• if the predetermined trigger pressure has been exceeded, and the mail tray filler is not in pause mode, and the current position of the take-away feeder is not closer than the predetermined minimum optimized distance, then feeding envelopes from the vertical stack using the take-away feeder;
• if the predetermined trigger pressure has been exceeded, and the mail tray filler is not in pause mode, and the current position of the take-away feeder is closer than the predetermined minimum optimized distance, then not feeding envelopes from the vertical stack and moving the mail tray filler in a downstream direction of the vertical stacker, thereby making room for more envelopes on the vertical stacker and to bring the vertical stack size into an optimal range;
• if the predetermined trigger pressure has been exceeded, and the mail tray filler is in pause mode, then not feeding envelopes from the vertical stack and moving the mail tray filler in the downstream direction of the vertical stacker, thereby making room for more envelopes on the vertical stacker;
• and
• if the predetermined trigger pressure has not been exceeded, and the mail tray filler is not in pause mode, then moving the mail tray filler in an upstream direction of the vertical stacker to bring the take-away feeder into contact with the vertical stack.