Apparatus for applying staples to groups of signatures and the like

摘要

Apparatus which applies staples to groups of sheets at the discharge end of a rotary printing press has a rotary conveyor which transports the groups of sheets past a stapling station where the groups are provided with pairs of staples. If one of the two regular stapling units is out of commission, an auxiliary stapling unit is started in response to detected absence of two staples in each finished product so that the groups of sheets receive pairs of staples while the defective stapling unit is being inspected, repaired or replaced.