This 'World' patent covers the exotic ROTOR hydraulic, 13-speed derailleur. And what a magnificent object it is.

A significant subset of the images picture the articulated pulley cage.

• Publisher: World Intellectual Property Organisation
• Inventor: David Martinez Garcia, Pablo Carrasco Vergara, Carlos Miguel Carton Cordero & Angélica Del Rio Garcia
• Country: Spain and, of course, all others
• Date: priority date April 2018
• Derailleur brands: ROTOR
• Derailleurs: ROTOR 1X13