Abstract: Apparatus for transferring successive sheets of successive stacks of overlapping sheets at a transfer station into the range of one or more conveyors for delivery to a book assembling, pad assembling, loose leaf binder assembling or other location employs a transporting unit with a stationary bottom defining an elongated path sloping downwardly toward the transfer station. The stacks are advanced stepwise or continuously in compartments between successive partitions pivotably secured to two endless chains which advance the partitions and the stacks between them toward the transfer station. The partitions are automatically pivoted to retracted positions beneath the bottom so that an intact stack immediately upstream of the transfer station can merge into the stack which is being singularized at the transfer station.