This is one of seven Japanese Patents and Utility Models, held by Sanyo, which describe various stages in the development of the Maruishi PC system. This was a 1970s electro-mechanical device that takes an electrical signal from a special gear electrical gear lever and then interprets it to pull the appropriate amount of bowden cable to move the rear derailleur to the correct position.

This enabled the rider to shift gears with both a very light touch - a Japanese obsession throughout the 197

• Publisher: Japan Patent Office
• Inventor: Yoshitaka Wakebe and Kazuhiro Tomoshige
• Country: Japan
• Date: Priority date March 1976
• Derailleur brands: Maruishi
• Derailleurs: Maruishi PC electro-mechanical system