STACKING APPRATUS AND STACKER LOAD CHANGE CYCLE METHOD

An automated sheets processing system has a vertical stacks accumulating region (SAR) into which sheets are uninterruptedly fed to build vertical stacks for pre-specified loads including completed loads and newly building nascent loads. A tiltable Stacking Deck 33 has a downstream discharge end 41 from which the sheets can be fed at different elevational levels into the stacks accumulating region 39. A nascent sheets accumulator system has a plurality of support surfaces that are retractably interjectable into the stacks accumulating region for defining a separation gap between the top of a completed load and the bottommost sheet of a nascent new load. At least one of the support surfaces is retractably interjectable in an upstream direction into the stacks accumulating region while at least two others of the support surfaces are retractably interjectable in a downstream direction into the stacks accumulating region. One of the support surfaces has an anti-scuff feature.