Stitcher-Gatherers

Heidelberg's stitcher-gatherers work at a speed of up to 14,000 cycles per hour. If a problem occurs at this speed, unusable copies quickly pile up in the delivery before the operator even notices that something is wrong. Heidelberg has therefore incorporated sensors to monitor thickness, sheet pulling, sheet placement, and binding. Thus any problems are detected immediately and the machine is automati- cally halted if necessary.

Heidelberg equips a series of Stitchmaster stitcher-gatherer models - from the ST 270 to the ST 400 - with a software-supported cascade control system to save even more paper. During startup, the cascade control system delays starting up each feeder until the first product reaches it in sequence. Afterwards, the stitcher-gatherer is shut down in exactly the same way in reverse: the gathering chain does not come to a standstill until the last product has arrived in the delivery. One after the other, the feeders stop operating. This approach prevents any incomplete items from being produced.

The high-end Stitchmaster ST 300 and ST 400 models are additionally equipped with sequential feeder monitoring. This reliably prevents the machine from placing any additional signatures on top of incomplete products turned out by an incorrectly operating feeder.

Another monitoring system from Heidelberg detects wrong sheets: even minimal deviations from the stipulated image cause the machine to be halted.