Reverend Rob
Posted April 9, 2013 - 7:14pm
The Bi-directional winding automatic system was new at the time, having been unidirectional first. This was spearheaded by Felsa, with their "Bidynator". Other Bidirectional movts were used, like the A. Schild. (can't remember the cal)
The Duo Wind, I believe, refers to the bidirectional winding, since all the models could also be wound by hand and was nothing new. I can't say for certain, but I'm pretty sure Bulova used its share of uni winding movts also. These especially would have been the US Bulova designed ones, like the 11AFAC. I'm having trouble locating the specs, but will update this when I do. The micro autos were certainly all uni.