Method and apparatus for manipulating stacks of paper sheets in wrapping

Abstract

Stacks of paper sheets are transported from a sheeter into a wrapper by the upper reach of an endless infeed conveyor. The front end faces of successive stacks catch up with and are decelerated by successive flights on an endless second conveyor which is driven at a speed less than the speed of the corresponding section of the infeed conveyor. This ensures that the dimensions of so-called tails, consisting of lowermost sheets of a stack which are shifted rearwardly with reference to the sheets above them, are reduced in size or that the tails are eliminated before the stacks enter the wrapping station. Misoriented stacks are reoriented ahead of the second conveyor by two endless lead-in conveyors having flexible belts trained over vertical pulleys and defining a channel the width of which decreases in the direction of advancement of the stacks. That portion of the path for the stacks where the stacks advance toward and thereupon move with the flights on the second conveyor is flanked by a pair of endless tapes, which are overlapped by the lateral portions of the stacks, and by two sidewalls. The sidewalls are movable toward and away from each other to thus alter the effective width of the path for the stacks. The tapes are movable toward and away from each other at a rate which is less than the rate of movement of the sidewalls.