This 1976 patent covers an early version of MAVIC's signature 800/850 design. It differs from the first production versions in a number of vaguely interesting ways:
The patent is issued to Georges Bloy. There is no mention of MAVIC. Georges Bloy also appears to hold only two other patents, one for a front derailleur and the other for a similar rear derailleur design - which may indicate that he was not a regular MAVIC designer.