Method and apparatus for direct shingling of cut sheets at the cutoff knife

摘要

Shingling of paperboard sheets cut from a web with a helical blade cutoff knife utilizes the downward deflection of the trailing edge of the cut sheet and simultaneous lifting of the leading edge of the web to position the sheets for shingling immediately downstream of the knife. A vacuum outfeed conveyor takes advantage of the initial downward deflection of the sheet caused by cutting to pull the trailing edge of the sheet onto the vacuum conveyor which is simultaneously slowed relative to the lead edge of the advancing web. In the preferred embodiment, vacuum is continuously applied and the conveyor is accelerated back to line speed as soon as the leading end of the web is pulled onto the vacuum conveyor.