Method of Making Die Plates for Card Punches : Jacob Rabinow

Method of Making Die Plates for Card Punches
ca. 1951

While still working for NBS, Rabinow was asked by the U.S. Census Bureau to design a computer controlled card-punch that would punch an IBM card all at once rather than the conventional method of one row at a time. He found the difficulty of this lay not in controlling the punches but in making a die plate that fir the punches very closely. Loose fitting punches would dull quickly and not leave clean holes, sometimes even leaving hanging chads. He designed some special methods for making close fitting die plates and delivered his high-speed card-punch to the Census Bureau.

The Census Bureau then asked Rabinow to design a sorting machine with the ability to sort cards into a larger number of pockets than was then possible. His conveyor-belt sorter with escort memory successfully accomplished the task and became the springboard for his efforts at Rabinow Engineering to automate the operations of the U.S. Postal Service.