I have not worked out exactly what is going on in this patent.

In the 1930s Victor Simon had obtained a series of patents showing simple, but well executed, designs, and had gone on to actually manufacture a number of exactly as simple, and well executed, Rota derailleurs.

In contrast, this patent seems to show a device of bewildering complexity - and I have no evidence that it was ever manufactured.

However this patent does tell us the Victor Simon's interest in derailleurs continued after the Second World War - at least unitl 1950. After this date Victor continued to take out patents, but they were not related to derailleurs or even to cycling.

• Publisher: L’Institut national de la propriété industrielle
• Inventor: L'Emboutissage Industriel Victor Simon
• Country: France
• Date: Priority date June 1950
• Derailleur brands: Rota
• Derailleurs: unknown