This is Jean Ras' first design for a leaf spring actuated derailleur. The main arm is very much in the style of a Super Champion derailleur of the time. But the two giant leaf springs add a refreshingly comedic note.

I don't think this design ever made it into production.

• Publisher: L’Institut national de la propriété industrielle
• Inventor: Jean Joseph Marius Pierre Ras
• Country: France
• Date: Priority date January 1943
• Derailleur brands: RAS
• Derailleurs: RAS Course