Multiple zone stack height sensor for high capacity feeder

摘要

A stack height assembly consisting of two transmissive sensors and two flags, the stack height of a feeder module can be set to three different levels depending on the weight of the media. This "optimization" of the stack height to address the media's failure mode results in increased latitude. When feeding lightweight media, the stack height is set larger in order to increase the gap to the feedhead. This allows more room for separation of the media using fluffer jets. This increased gap also reduces the chances that the un-acquired media will be fluffed into contact with the acquisition surface and subsequently be shingle fed into the take away roll due to the friction between sheets. When feeding heavyweight media the stack height will be set smaller. This reduces the gap to the feedhead and reduces the time required to acquire.