This is the second of two patents held by Louis-Eugène Morel. It shows his signature sealed aluminium body and rubber boot covering the sliding rod mechanism. The sliding rod is driven by a toothed wheel rotated by the cable.

This patent covers a mechanism with a proper double pulley cage. This cage has a rather natty mechanism that allows it to be opened to remove or replace the chain.

• Publisher: L’Institut national de la propriété industrielle
• Inventor: Louis-Eugène Morel
• Country: France
• Date: French application August 1950
• Derailleur brands: Morel
• Derailleurs: Morel twin pulley design