Endless drive belts are provided in a spaced-apart relation to each other such that one endless driven belt is set in contact with one of these drive belts and the other endless driven belt is set in contact with the other drive belt. The one drive belt is driven by one pulse motor through one drive...http://www.google.es/patents/US5407191?utm_source=gb-gplus-sharePatente US5407191 - Device for conveying sheets one by one
