This 1951 patent, for a single pulley derailleur that forshadows the Campagnolo Sport, bears a striking resemblance to Francesco Ghiggini's 1941 patent. Perhaps this is not surprising, given that Tullio Campagnolo bought Ghiggini's derailleur patents in 1951.

• Publisher: UK Intellectual Property Office
• Inventor: Tullio Campagnolo
• Country: UK
• Date: Italian application September 1951, UK application September 1952
• Derailleur brands: Campagnolo
• Derailleurs: prototype Campagnolo Sport