This is Jean Ras' second design for a leaf spring actuated derailleur. It is a much cleaner design than his first effort. This time the main arm looks much more like a Huret, and there is only one leaf spring.

An advert placed in L'Auto indicates that this design was used to some success in professional races.

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