French Patent # 2,878,499 - MAVIC

French Patent 2,878,499 - MAVIC main image

I have not taken the time to fully understand this patent. It dates from 2004, after the the MAVIC Mektronic. Unlike the Mektronic design, it appears to describe a derailleur that combines MAVIC's signature use of the guide pulley to provide power with a parallelogram action.

I don't think it ever made it to production - a great pity.