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What is the purpose of a double feed nut on a cylinder phonograph? I have tried to research this and can't find an answer right off. Smoother tracking??

Lee wrote: Fri Aug 02, 2024 9:43 am What is the purpose of a double feed nut on a cylinder phonograph? I have tried to research this and can't find an answer right off. Smoother tracking??

I don't know that actual reason, but I have the following thoughts, for what they're worth.

1. These seem to appear on larger machines, like Triumphs & Concerts, that have heavier carriages and larger horns. Double nuts would experience less wear for these heavier applications and would be less likely to skip.
2. If the feed screw should receive damage, such as a small nick in the very fine threads, the first nut could ride over the damage while the second nut continues to feed the carriage. Then, visa-versa when the second nut hits the damaged spot. In this scenario, a single nut may just jump and skip with no feed taking place.

Thank you greatly for your answer, makes sense. Interested in any more thoughts from the group.