This is a patent for a bizarre design that looks like Cyclo’s take on a simple, possibly cheap, racing derailleur. A kind of ‘suicide’ rear mech.

The long arm is moved across a gate with three different slots - see figure 6.

I don’t think this mechanical marvel ever made it into production, perhaps we should be grateful.

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• Publisher: L’Institut national de la propriété industrielle
• Inventor: Albert Raimond
• Country: France
• Date: French application July 1935
• Derailleur brands: Cyclo
• Derailleurs: unknown