A transporting system in a packaging machine automatically merges and accumulates, usually as a shingled stream, generally flat articles having substantially continuous and discontinuous opposite sides, and includes a portion, of one of two main conveyor mechanisms, that is constructed to invert the articles, from side-to-side about endwise axes so that all of the cartons face upwardly, even though the articles of alternating groups have been inverted, during transport by that main conveyor mechanism, about their lateral axes.