Sturmey-Archer is very famous for its hub gears - and is also suspected of an aversion to derailleur gears. But here is a patent for a derailleur design dating from 1950. There is also a 1948 patent here.

• Publisher: UK Intellectual Property Office
• Inventor: Henry Oxley of Sturmey-Archer Gears Ltd.
• Country: UK
• Date: Priority date July 1950
• Derailleur brands: Sturmey-Archer
• Derailleurs: unknown