This is the last of three patents, held by Chang-Hui Lin of KCNC, relating to derailleur designs. It describes a fully developed, production-ready, design using a cable rotating a cylinder mounted in the b-pivot which uses a spiral groove to drive the p-pivot inwards and outwards. I rather like it.

This design was featured, in schematic form in the 2012 KCNC - E-catalogue. Unfortunately I don't think that KCNC ever put it into production.

• Publisher: Taiwan Intellectual Property Office
• Inventor: Chang-Hui Lin
• Country: Taiwan
• Date: Priority date August 2011
• Derailleur brands: KCNC
• Derailleurs: unknown