This is the first of a series of three designs for hanger plates for the Simplex Champion du Monde. The others are, unsurprisingly, French Registered Design # 31973-003 and French Registered Design # 31973-004.

• Publisher: L’Institut national de la propriété industrielle
• Inventor: Lucien Juy
• Country: France
• Date: French application November 1938
• Derailleur brands: Simplex
• Derailleurs: Simplex Champion du Monde