This is the third of three derailleur patents filed by the ‘Perm Machinery Factory named for the October Revolution’ in Perm, Russia. In addition to Perm employees, this patent lists Georgy Panin of TSKTB in Kharkov, Ukraine, implying that it is some kind of joint effort.
Unlike the other two Perm patents, this one does not feature adjustment screws that are positioned in the style of a Gian Robert derailleur. In contrast, the adjustment screw mounts featured here are very similar to (but slightly different from) those of the Perm derailleur in this collection.
Browse associated derailleurs.