Abstract: A sheet material handling apparatus includes a main conveyor along which collated assemblies of signatures are sequentially moved. An inserter assembly is provided to feed inserts one-at-a-time into each of the collated signature assemblies in turn. The inserter assembly includes an infeed conveyor which feeds a continuous strip of interconnected inserts from a source. A separator assembly separates the leading insert from the remaining inserts in the strip of inserts. A separator conveyor moves the leading insert forwardly away from the strip of inserts toward a feeder conveyor. The feeder conveyor accelerates the insert to a relatively high speed and then propels the insert into an opening in the collated assembly of signatures. To form the opening in the collated assembly of signatures, a plow or deflector plate is mounted on the outer end portion of the feeder conveyor and engages the collated assembly of signatures.