Just for additional research, it was always interesting to me how
Lewis B. Doman is credited for the design of the Ampico player
mechanism, and Charles Stoddard held Duo-Art patents when he came
to take over the design and development for Ampico.
Stoddard made the Ampico system practical and put it into production,
primarily with his inventions for making and coding the rolls, but
also his arrangement inside the piano, too. Stoddard's biggest and
most valuable contribution, in my opinion, was the design of the
cutting machine for dance music with the floating trackerbar, and
the design of the editing room and its procedures of making a roll.
Lewis Doman's Ampico contribution, however, was a brilliant basic
invention based around the tensioned expression lever and its three
"squares" that tension the regulator valve, balanced against a set
point regulator, all relative to stack pressure at the time, making
[ I imagine a meeting of the Board of Directors of American Piano
[ Co. in late 1921, when an economic recession caused piano sales
[ to plummet. A glum director asks, "Why are we paying these guys
[ so much? Inventors and engineers are a dime a dozen today."
[ The company president explains, "Because Doman and Stoddard
[ personally control the patents on critical devices used in our
[ Ampico piano, we hired them and we pay them what they demand.
[ Since they work for us we can watch them and keep them content.
[ Then they won't sell out to our competitors."
[ I believe M. Welte & Sons also held patents licensed to Ampico.
[ See http://mmd.foxtail.com/Pictures/Welte/patents1.html
[ -- Robbie