This machine punches 21 cards from a sheet in 12 seconds, three at a time, incrementing automatically between each of the 7 rows.
Meanwhile, a seated operator carefully places the next sheet in position, using the cross hairs in the pair of binocular magnifying periscopes to align exactly with the registration marks printed on the sheet.
The distance between the periscopes had to be adjustable to cope with the variation in sheet size which occurs during lamination in the previous stage, adjusted by means of a simple handwheel. The adjustment, typically up to 3mm, is also stored in a “mechanical memory” within the table supporting the sheet. As soon as the adjustment is correct and the previous sheet has been completed the operator presses the start button. This turns on a vacuum, sucking the sheet firmly onto the table, which then transfers it horizontally to the punch station. The “mechanical memory” stored in the table is transferred to the automatic feed mechanism, adjusting its incremental stroke.
The machine is fully pneumatic, not only the air cylinders which actuate the motions, but also the control system – sensors, timers, valves. The only electrical function is the pair of spotlights illuminating the marks on the sheet.