This patent describes the Fichtel & Sachs Aigle. It is a French patent that has a priority date set by an earlier German patent. However I have been unable to locate this German patent - so this is what we have.

• Publisher: L’Institut national de la propriété industrielle
• Inventor: Fichtel & Sachs A.G.
• Country: France
• Date: Priority date December 1938
• Derailleur brands: Fichtel & Sachs
• Derailleurs: Fichtel & Sachs Aigle