Abstract: An assembly is provided of a known high speed envelope blank cutting unit with a known envelope folding unit and an envelope conveyor to transport a continuous stream of envelope blanks from the blank cutting unit to the folding unit in a predetermined timed sequence and in position for proper entry into the folding unit. The conveyor includes predetermined transport segments positioned, relative to one another, to accommodate necessary path direction changes, and a stacking or shingler segment. Opposed belt systems in each transport segment maintain the blanks in a desired relative relation. The belts are driven from the blank cutting unit, with each transport segment driven by or driving adjacent segments. The timing between the blank cutting unit, the folding unit, and the envelope conveyor is selected and adjusted through an adjustable drive shaft arrangement interconnecting the two units.