A conveyor apparatus includes a receiving clearance adjustment mechanism for adjusting the vertical clearance between portions of downstream-side upper belts, the portion being located furthest upstream with respect to the conveyance direction of signatures, and upstream-side lower belts. The conveyor apparatus also includes a separation start position adjustment mechanism for adjusting a position at which upstream-side upper belts start to separate away from a signature. The conveyer apparatus can convey sheets, while properly transferring them between upstream-side belts to downstream-side belts, without generation of unintended positional shift, even when changes arise in the thickness and/or length of the sheets.