Quote:
the missing perf hole is likely a result of a badly bent perf pin
Opinion:
With respect, I would suggest "Bent perforating pins" is a misnomer.
With experience as an apprenticeship in Engineering,
Rather "Broken perforation pins" would be a more accurate description.
To wit.
Bent pins
It is sometimes suggested that perforation pins might have bent. Having consulted engineers on this, the authors are satisfied that they did not and that, even if they had, there would be little discernible evidence on the stamps themselves. Perforation pins were made of hardened steel and would have been more apt to break rather than bend.
The pins were permanently guided and supported by the stripping plate in which they were sheathed throughout the whole perforating cycle. In practice, therefore, only that portion of the pin which extended below the stripping plate and effected the perforation could be subject to bending.
Any significant bend or distortion would have prevented a pin from mating properly with the holes in the die plate. If it did not mate, it would strike solid metal and break. What might sometimes be thought to be evidence of bent pins is in fact due to imperfect alignment of the perforation holes relative to each other.
The Archer Combs A and B illustrated in Figs. 3.1 and 3.2, page 22, are good examples of this. The misalignment is entirely a manufacturing fault.
Ray Simpson and Peter Sargent
The only exception, may have been with the very early treadle type line perforators.
Posted 12/18/2022 9:00 pm
